It contains sketched versions of each of the characters, presumably used for testing before the final assets were drawn. Old is the name of a folder present in the files of Monika, Natsuki, and Sayori's sprite folders ( images.rpa/images/).
The background is only sketched, and Yuri's shading differs from the final image. Credits_temp1.png, located in images.rpa/images/menu, is an image unused in the game which appears to be a low-resolution prototype version of Yuri's first CG.
