Jeffrey Depoalo

Chosen answer: Simple, he kept the photo in the box but not in the secret compartment. We never see the photo and we never know when it was in the secret compartment so it's possible he was looking at it and moved it when he was about to show Spongebob. Even if he wasn't looking at it, Patrick might have just been looking at the string and laughing or even just thinking about the picture. Patrick and Spongebob do in many instances laugh at the simplest things.

Lummie