The detail is really good

If you'd like to have this piece available to provide context for the newer ones, you can upload it elsewhere (e.g. imgur or Twitter) and link to it from the descriptions of the new pieces. This way, people can see it, but your gallery can have only those pieces that follow PJ's rules.

I should mention though, it's entirely possible the PJ mods will disagree with my assessment and accept this despite its issues. The above is a suggestion of what you can do if it's not accepted.

Thank you for taking the time to critique my work. This is an ancient piece to remind me from whence I came. A series of them is in the works, but I do want to keep this one up. Thank you!

This looks like a reduction from a piece with more colours, one that hasn't even been cleaned up - the "solid" areas are full of dithering artefacts and aren't consistent from frame to frame, and there random pixels that seem to appear in one frame each. Reductions like that aren't allowed in the PJ gallery.

In addition, the background doesn't seem to serve much purpose, in which case, the rules request that you leave it empty instead. There probably doesn't need to be so much empty space either in that case, you could crop the image. The padding makes it more annoying to view the image zoomed in, since it pushes it off-screen without improving the composition.

The drawing and painting of this piece are well-done, but it doesn't have the pixel-level control that the PJ gallery focuses on.