It would be great if delta chat would integrate with native addressbook on the system because:
- It could pick profile pictures that are already there.
- It could recognize messages from the same people even when they respond with different emails.
At the moment it does not appear that native address book is used at all. So every correspondent appears as circle with initials.
Even better if public keys could be stored in corresponding address books so other apps could potentially take advantage of it too. VCard even has key field for that.
I think messages app on both iOS and mac does a pretty good job at both surfacing profile pictures for both direct messages and group messages. It also integrates with system wide contacts which in turn other apps make use of as well.