From the Super Mario Wiki
A Camera Block is a type of block that appears in Mario & Luigi: Dream Team that Kylie Koopa placed. When hit, it takes a picture and encrypts it, then gives Mario and Luigi the encrypted picture. Kylie Koopa shows the Bros a Camera Block and tells them to decrypt the picture by solving a puzzle. The player has an infinite amount of time to solve the puzzle, but if the player solves the puzzle in a certain amount of time, Kylie gives the Bros. a prize. The Puzzles gets harder and the pieces get smaller with each increasing level.