Note: This is not about changing the design, the thumbsize for users is 70px (7rem?) and that's not going to change. It's about the size of the thumbnail being fetched from the servers.

Portals search loads thumbnails at 80px (or 160px @ 2dppx). This is not standard size and causes extra thumbnailing and fragmentation of thumbs which is hurting media storage (swift currently has issues with file count in each container, the size is not that much of an issue). I explained it in depth with numbers in T211661#8377883

You should use 120px for 1x and 220px for 2x.

This improves performance of loading thumbnails, reduce latency and so on.