When picking or editing a gaming or anime PFP, focus on a clear silhouette and...

https://alpha-wiki.win/index.php/Why_Does_My_Avatar_Lose_Detail_When_It_Gets_Compressed_on_Mobile_Notifications%3F

When picking or editing a gaming or anime PFP, focus on a clear silhouette and crop tightly around the face to keep it recognizable when small. Use a simple background to avoid distractions, and test how it looks in both light and dark modes