Until I got my bunny I never knew they had rabbit body language. They do this for numerous reasons such as they are happy, they are angry, or it could be because they are scared. Here is a list and description of rabbit body language:
They do this to show you that they are happy. They do a little jump and spin in the air. this is hard to get a picture of since they do this really fast.
Standing on Back Legs
They will do this so they can get a better view of the room if they think there may be danger, or they will do this to try and get the treat/food that you might be holding.
Flat on the ground
This could be because your rabbit is saying "Don't hurt me...your the boss here......I surrender!" or it could also mean your rabbit is enjoying getting his head stroked and is happy.
Upside down, legs in air
This means they are in total happiness and often do this after a lot of binkying!
This can mean that your bunny is telling you that he is frightened or there is danger. I have also noticed that my male rabbits thump when one of them rubs their chin on the hutch and the one inside the hutch dosn't like it.
If it is a low tooth grinding, this indicates that they are happy. This is like a cats purr. If it is loud grinding, this indicates that your rabbit is in pain.
This can mean that they are talking to you or they are annoyed. Female rabbits may sniff when you are picking them up.
Normally because they are angry. They may bite.
They will do this when you have placed something they haven't seen/smelt before near them and they go to investigate it. There ears will be forward when they are doing this.
interesting fact- Rabbits will usually sleep with their eyes open. The only giveaway that they are sleeping is that they often twitch and their noses stop wriggling.
Here are some very nice rabbit products which I thought you might like so have a look!