(Please post comments on ONLY the picture quiz hereinbelow. To post comments on the crossword puzzle, please click here.) Not exactly a pushover for a Sunday, but enjoyable, with many fine surface readings. Thanks to Commoner. Definitions are underlined in the clues.
Across
1 Jack‘s a long way off being taken in by psychic (8)
SEAFARER : AFAR(a long way off) contained in(being taken in by) SEER(a psychic).
Defn: A sailor, or in nautical terms, a Jack.
6 Live on BBC1, say (6)
RESIDE : RE(about;concerning;on as in “… re your submission …”) + SIDE(a Briticism for a TV channel, presumably from the days when there was only BBC1 and ITV in Britain, as in “what’s showing on the other side?”).
Defn: To live in a dwelling.
9 Contest such a claim made up by taxmen (7,6)
MUSICAL CHAIRS : Anagram of(made up) SUCH A CLAIM plus(by) IRS(abbrev. for the Internal Revenue Service, the taxmen).
10 Runs into an exam, being late (2,4)
AT REST : R(abbrev. for “runs” in cricket) contained in( into) [A TEST](an exam).
Defn: The state of being dead;late.
11 A bottle smashed on soft work surface (5,3)
TABLE TOP : Anagram of(smashed) A BOTTLE plus(on) P(abbrev. for “piano”, musical direction to play softly).
13 Sitting by river, I’m about to tuck into fruit – this may bring death! (4,6)
GRIM REAPER : R(abbrev. for “river”) placed after(Sitting by …, in an across clue) [ I’M + RE(with reference to;about) contained in(to tuck into) GRAPE(a fruit) ].
Defn: The personification of death.
15 Having a change of heart, snatch dress (4)
GARB : GRAB(to snatch) with its 2 inner letters changing places(Having a change of heart).
16 Diver number 24 comes first (4)
LOON : N(abbrev. for “number”) placed after(… comes first, in an across clue) LOO(answer to 24 Down).
17 Again stirred around three, at heart dead exhausted (10)
OVERWORKED : OVER(again, as in “had to do it over”) + [ WOKE(stirred;got up from sleep) containing(around) the innermost letter of(at heart) “three ” ] + D(abbrev. for “dead”).
19 Criticise line in rendition of Let It Be (8)
BELITTLE : L(abbrev. for “line”) contained in(in) anagram of(rendition of) LET IT BE.
21 Affected by Times online comments (6)
TWEETS : TWEE(affected;overly sentimental, sweet or pretty) plus(by) T’S(plural of T;abbrev. for “Time“).
Defn: … on the Twitter website.
23 Fictitious addition: Butcher Bill meets with hard men (13)
EMBELLISHMENT : Anagram of(Butcher) [BILL MEETS plus(with) H(abbrev. for “hard”) + MEN].
25 Where an artist may work, one wearing earring and ring (6)
STUDIO : I(Roman numeral for “one”) contained in(wearing) [ STUD(an earring) plus(and) O(letter representing a ring) ].
26 Anxious son with long hair (8)
STRESSED : S(abbrev. for “son”) + TRESSED(describing one with long locks of hair).
Down
2 Dorothy’s aunt was introduced to old worker? (5)
EMMET : EM(short for Emily, Dorothy’s aunt in the series of books starting with “The Wonderful Wizard of Oz”) + MET(was introduced to).
Defn: An archaic;old word for “ant”, a member of social insects one of whose caste is the worker).
3 Angler‘s koi finally put in fine tank? (9)
FISHERMAN : The last letter of(… finally) “koi” contained in(put in) [ F(abbrev. for “fine”) + SHERMAN(the principal military tank used by the Allies in WWII) ].
4 This is one way to make waves! (4,3,4)
ROCK THE BOAT : Cryptic defn: The literal interpretation of the figurative sense of causing trouble.
5 Bunk incorporating 50s work desk (4-3)
ROLL-TOP : ROT(bunk;rubbish) containing(incorporating) 2 x L(Roman numeral for 50) + OP(abbrev. for a musical work;composition).
6 Isaac’s mum needs to show no sex appeal to make whoopee! (3)
RAH : “Sarah”(biblical wife of Abraham and mother of Isaac) minus(needs to show no) “SA”(abbrev. for “sex appeal”).
Answer: Another exclamation of encouragement;excitement, similar to “whoopee!”. And of course, “making whoopee” is slang for making love, which makes the clue’s surface a deliberate self-contradiction!
7 Thorn from small tree (5)
SPINE : S(abbrev. for “small”) + PINE(a coniferous tree).
Defn: … as one would find, say, on a porcupine.
8 Dance sure to be spoiled by conversation (9)
DISCOURSE : DISCO(a dance style) + anagram of(… to be spoiled) SURE.
12 Prison guard – one who twitches? (4,7)
BIRD WATCHER : BIRD(rhyming slang for a prison, from “birdlime” rhyming with “time” in prison) WATCHER(one who guards).
Defn: …, in other words, a “twitcher”.
14 First lady originally laying in bed with president (9)
ROOSEVELT : [ EVE(the biblical first lady) + 1st letter of(originally) “laying ” ]contained in(in) ROOST(a bed;a place for resting at night, especially for birds).
Answer: Franklin or Theodore, former presidents of the USA, take your pick.
15 Perhaps nursery workers gather before start of school, requiring requiring Dutch courage ultimately (9)
GARDENERS : [ GARNER(to gather or store, as with grain, say) placed above(before, in a down clue) 1st letter of(start of) “school ” ] containing(requiring) [ D(abbrev. for “Dutch”) + last letter of(… ultimately) “courage ” ].
Defn: … in a garden, and not, as the surface suggests, of nursemaids drinking.
18 Idly see out when these are open! (7)
EYELIDS : Anagram of(out) IDLY SEE.
20 10, as 15 Down may be? (2,3)
IN BED : Cryptic defn: Where gardeners(answer to 15 Down) might be working in.
Answer: … and therefore at rest(answer to 10 Across).
22 Heading for championship (5)
TITLE : Double defn: 1st: … for, say, a chapter or a piece of writing.
24 Endless deluge creates bog (3)
LOO : “flood”(a deluge;an overwhelming quantity, say, of water) minus its 2 endmost letters(Endless …).
Answer: Slang, as is “bog”, for a lavatory.
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The following pictures have unidentified links to the puzzle.

(Please post comments on ONLY the picture quiz hereinbelow. To post comments on the crossword puzzle, please click here.)
Sorry, mostly stumped by this one. #1 is obviously a surviving Guimard Metro station entrance (EMBELLISHMENT? OVERWORKED?), and #2 is a map of the London Underground. Frankin D. ROOSEVELT is on the other side of the dime depicted in #3, but why the nickel? Google tells me #4 is an aerial mine, and #5 is clearly Charlie’s Angels, but I’ve no idea of the connection of either to the puzzle.
1) The station looks like Monceau, one of several whose entrances were designed by Hector Guimard, an exponent of Art Nouveau which was combined Art with EMBELLISHMENT.
3) A picture of a Jefferson Nickel and a (Franklin D) Roosevelt Dime. Not sure why you included the nickel. Perhaps coins with TITLEs?
5) Charlie’s Angels, a TV series primarily viewed by BIRD WATCHERs?
2) Is the Google doodle used to celebrate the 150th anniversary of the London Underground, stylised to spell ‘Google: an EMBELLISHMENT of the real thing?
Hi Ian SW3 and Freddy.
Pic1: The Paris Metro system includes the Franklin D. ROOSEVELT station
Pic2: Google is developing the Project LOON to connect remote areas to the Internet by high-altitude balloons
Pic3: Sorry about the nickel red herring; the dime was the actual link, as you both said
Pic4: During WWII, the dropping of mines into the sea by air was called gardening, and the GARDENERS were the RAF
Pic5: Those flared-from-the-knee pants were called LOON pants.
Thanks scchua: such a ‘lovely’ euphemism for warfare!