Context: According to ascii2d.net, the full resolution of this image is about 1700x2100. There were other things on the artist's twitter that aren't on their pixiv, but I can't locate this image anywhere else.

The filename I had for it before uploading:

77046297_p0 16d857654984828d5

Additional info from ascii2d:

3f9c585e00e9156615994c516ffc68dd
1700x2100 JPEG 829.8KB