well the 2% one was Going into the menus in Act 2 will have a chance to flash this picture of Monika for a split second. This will only happen one time. :/

After the poem minigame in Act 2, there is a 1/6 (16.67%) chance of a reel of an uncorrupted 'hxppythxughts.png' version to scroll down for a brief moment, with distorted, creepy music playing in the background before Yuri welcomes the player back. The picture is only Sayori's head as seen in one of the special poems.