Note for artist request: at time of writing the source link's account muu_poppo does not exist. At the end of January they posted this which seems to mention deleting their account. The account details in the background of this tweet suggest the account was created in March 2019. The bio is:

お絵描き練習場所。アークR中心に好きなものを描き殴って置いておくだけ。本アカ→ @ayacco58 コスプレも好きなので自分の資料用に衣装構造メモも置いときます。

I can't read jp but I think it's saying muu_poppo was an art account and ayacco58 (also defunct) was a main account which seems to've mostly posted cosplay. The image in that post is recognized by saucenao as this (deleted) pixiv post by this artist whose account is empty. That's all I could find.