There is a puzzle before like this but the prize is bitcoin but I am not sure if they got the answers already on that riddle.
Is that the Phemex exchange puzzle?
There is nothing special about this picture, it seems like it is a normal photo and they are trying to create curiosity to attract readers, Also it seems they are trying to promote their twitter. by calling follow if we can't solve the puzzle
This can be true but projects like this do really make their promise for puzzles like this with real money, with real Ethereums. Decoders that are good with puzzle-solving can do this but it's not going to be easy because it's a lot of money.