Can I see if another Resonate user is my Facebook Friend?

Yes! (so long as you have allowed Resonate access to your Facebook Friends)
Whenever you see the small blue Facebook icon in the top left hand corner of another user’s profile picture (Discover People, Connections and Chat), that immediately tells you that this user is your Facebook Friend. Conversely, if there is no small blue Facebook icon in the top left hand corner of another user’s profile picture, then you will know that this user is not your Facebook Friend.
You can also see Mutual Facebook Friends between yourself and any other user.  When viewing another user’s Profile, if there are Mutual Facebook Friends between you, you will see the number of Mutual Facebook Friends, tap view to see a list of your Mutual Facebook Friends.
Use Mutual Facebook Friends to vet or learn more about another user before or after connecting!