3/4 through the game, just before the festival, you are given a choice. The first one is to return to the mansion, the second being to check out the village. In order to unlock the last 4 photos, you'll need to make both choices.

So simply save at this moment in the game. Select the Mansion to get the Fox-Girl pictures and then go ahead and beat the game. Reload the save, select the Village option to get the photos of the two guards. Beat the game and viola. Instant completion.