Apparently gulping the faded Polaroid makes it unable to open the door in depths which I guess makes sense since you can't put it in the door if you swallowed it :
Steam Workshop::the polaroid (and the negative) but awesome
The 10 Best Trinkets in "The Binding of Isaac: Rebirth" - LevelSkip
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Steam Workshop::Polaroid Negative Rework
Trinkets - Binding of Isaac: Rebirth Wiki
Steam Workshop::the polaroid (and the negative) but awesome