Thank you for the clarification — I understand now that the images were intended to represent the illustrations used in the video/audio files, not the jacket itself.
However, we generally try to keep the number of images on album pages minimal. Usually, we only include the official cover or jacket image. We don't recommend uploading scans of booklet pages either.
Multiple images are only considered when an album officially has several interchangeable covers (for example, special editions or reversible jackets).
In the case of this album, I don't think there may be a clearly defined cover, which makes it a bit of a gray area. But even so, adding several background illustrations might still be too much for a standard album entry.
Also, I noticed that you've removed the non-Touhou covers from your user page. Would it be okay if I go ahead and delete those images from the site as well?
Thanks again for your contributions and understanding!