When loading a save using the "From File" option, the gallery will only update from the first file loaded. Loading any additional files will not update the gallery. In order to get the gallery to update from an uploaded file again, the browsers cache/cookies must be cleared.
This also results in situations where saves galleries can be overwritten. For example if a file with a incomplete gallery (file A) is loaded before a file with a more complete gallery (file B), saving a new file after progressing from the save in file B will result in a new file with the same incomplete gallery as file A, losing unlocked images as a result.
I'm not sure what the intended behavior of this system is or how it's currently implemented under the hood, but I believe a sufficient solution would be for the game to keep track of the unlocked images independently of save files, and update this collection every time a save file is loaded. Additionally, every time a new file is saved, it would contain all of the unlocked images from this global collection, making it easier to fill out the gallery.
It should be noted that I only ever play this game in browser, in private mode, so I haven't done any testing with the local save system. I've also attached two files to aid in testing with the same details as above, where file B has a more complete gallery than file A.
EDIT:
I forgot to mention that I usually use Microsoft Edge to play, but I also was able to confirm that this also happens on Google Chrome
This also results in situations where saves galleries can be overwritten. For example if a file with a incomplete gallery (file A) is loaded before a file with a more complete gallery (file B), saving a new file after progressing from the save in file B will result in a new file with the same incomplete gallery as file A, losing unlocked images as a result.
I'm not sure what the intended behavior of this system is or how it's currently implemented under the hood, but I believe a sufficient solution would be for the game to keep track of the unlocked images independently of save files, and update this collection every time a save file is loaded. Additionally, every time a new file is saved, it would contain all of the unlocked images from this global collection, making it easier to fill out the gallery.
It should be noted that I only ever play this game in browser, in private mode, so I haven't done any testing with the local save system. I've also attached two files to aid in testing with the same details as above, where file B has a more complete gallery than file A.
EDIT:
I forgot to mention that I usually use Microsoft Edge to play, but I also was able to confirm that this also happens on Google Chrome