That's what I call rabbit kisses! My more confident rabbit does it with me, and they both do it do each other when saying 'hello!'
I love being sniffed, and my vet gives them rabbit kisses (nose to nose) when he sees them which is one of the ways I knew he was bunny savvy
Have a look at this page:
http://toomanybunnies.com/understanding-bunny-languag.html
I like the bit about love bites, cus that's what you described in your other thread I think?