It’s been awhile since the last one:
What is special about this photograph?
I think this is fairly hard, but I’m not sure… good luck, I’ll post the answer soon.
Sorry, no prizes, warranties or even correct answers guaranteed – your mileage, as always, may vary.
PS- If you’re clever enough you can find the answer by cheating. But then that’s cheating…
I discourage cheating – better to just look at the solution here instead: