Considering that a similar image has been extracted by the same uploader and that this image is very similar to the one on https://www.spriters-resource.com/nintendo_switch/fireemblemthreehouses/asset/136327/ I believe this to have been extracted by the uploader.

DivineEspadas said in comment #2613136:

and that this image is very similar to the one on https://www.spriters-resource.com/nintendo_switch/fireemblemthreehouses/asset/136327/

They're the exact same file.