Great collection! Thank you for sending docs to legal@decentraland.org to confirm you have consent from the Winehouse family to proceed with this design.
Thumbnails should have a fully transparent background in order to work in world and the recommended size is 512x512px, though 1024x1024px is also possible.
Some parts of the male representation are a different tone of grey and show some flickering, could be double faces, transparency or normals.