Hey, thanks for working on this!
A "brand" re-design is something that we could really use. One of the things that I would like to change from the current icon/logo, though (and that this new one doesn't change), is the fact that there is a mobile phone in it.
You can use KDE Connect between two computers, or between two phones (although it's not the main development focus at the moment). So I think a more generic icon that embodies "syncing" without any specific device would suit us better, IMO. Plus I find a bit weird to have a phone app whose icon is... a phone.