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 :
Frequent Enough Isaac Facts on X: "You can unlock the special door to Ascent using the trinket "Faded Polaroid." https://t.co/kY9u7iJm7W" / X
Steam Workshop::Overexposed Negative
Just got the polaroid!!! : r/bindingofisaac
The Binding of Isaac: Repentance Tainted Characters Guide – GameSkinny
Mom Gives Regular Prizes: Repentance - Skymods
I have found what appears to be a faded version of The Polaroid - as a trinket : r/bindingofisaac
About: Complete Guide For Binding of Isaac Rebirth (iOS App Store version) | | Apptopia
Category:Added in Afterbirth - Binding of Isaac: Rebirth Wiki
About: Complete Guide For Binding of Isaac Rebirth (iOS App Store version) | | Apptopia
Endings - Binding of Isaac: Rebirth Wiki
I got both The Polaroid and The Negative by using Diplopia. : r/bindingofisaac