At the moment, profile posts and community posts look almost alike on the profile stream.
Finding a way to better distinguish those two from another at a glance would prevent some confusion and create a better user experience while browsing profile streams.
Some ideas to achieve a better differentiation:
1. The use of different colors or color shades for community and profile posts
2. A headers design that differs more than it does at the moment
3. Community posts could be slightly indented on the profile stream
I'm sure there are other ways to deal with this issue but this is what came to my mind.
Feel free to add your own ideas in the comments.