So then it should refer to a press release, release announcement, github commit, or whatever. Just linking to the site and saying "Snowden supports it!" isn't really useful.
Yes, on Android at least the photo selection is better now, you can mark up photos and in general it's on par with other messengers.
In the past year or so it's definitely filled out, feature-wise. Audio message UI has been improved.
Interesting say more
Encrypted backup and restore works now. Including media.
For how long though? Signal Android has repeatedly broken its backup functionality with no warning, it seems the Signal team is not testing this feature regularly.
iOS users are still out of luck on message backup too :c