My partner and I have a 6 month old male rabbit who is very friendly. He lives outside most of the time but he gets to come inside daily and have a play in the living room + kitchen for at least a couple of hours which he enjoys, and he loves being around people.
What he doesn't like is being picked up. When we have to pick him up he'll be very specific about how he's held, but he's still visibly uncomfortable (though not aggressive). We understand why he doesn't like being picked up (prey instinct etc), but we don't understand what happens next.
After we put him back down, he'll wander into the middle of the living room and do the biggest flop we've ever seen. Usually this mean's he'll do a full 270 degree roll from standing to laying on the opposite side he started rolling from. My understanding of rabbit behaviour (I'm pretty new to the gig) is that a flop is a sign of contentment, but he's clearly pretty grumpy about the whole ordeal. What gives?