When analyzing Alice Margatroid’s spellcard background from Imperishable Night, I noticed that the texture which is spinning counterclockwise looked like the texture from Wriggle’s background which is slowly moving downwards.
However, upon further investigation, it seems that the texture is the one which appears in Sakuya’s spellcard background and not the one from Wriggle’s. If you take Sakuya’s texture (left side) and compare it to Wriggle’s texture (right side), you can see they both derive from same initial image (hence the similarities), but now they are two different textures.
Also, while still on this topic with this particular image, Yukari Yakumo’s spellcard background contains it, but this time it is not a separate texture anymore, it is part of the image with Yukari.
And regarding Yukari’s spellcard background, it seems that it has the same motif as the jewel case cover of the Perfect Cherry Blossom CD. Although the positions do not perfectly match, if you put the two pictures side by side you can see the similarities: Yukari’s pose and the diagonal line.