The bug

Trapped chests seem to have a gray square on the front which is usually obscured by the lock, but makes itself seen when the chest is opened. This square does not exist on normal chests.

How to reproduce

1. Open a normal chest
2. Exit the chest
3. Before the chest closes, pay close attention to the region usually covered by the lock
4. Rinse and repeat, but with the trapped chest

Expected results

This gray square would not exist on the trapped chest texture.

Actual results

It does.