The SpongeBob Viewer is a toy that was sold in Burger King kids' meals during October 2011. The toy was a play camera made in the shape of a rectangle. SpongeBob's eye acts as the lens, and in the back a clear square allows you to see different images of SpongeBob, Patrick, Sandy, and Gary on vacation. The picture changes once you press on a button on top.
The toy's description from Burger King's no-longer-running Club BK website:
"Look through SpongeBob's camera to see vacation snapshots from Bikini Bottom."