Ozzie is adorable! He looks happy and content to me. My female U2 clicks her beak when she's really happy about something, mostly favorite foods or new toys but sometimes she does it with favorite people.
Ok, and I wondered about the people! I've seen him do it in response to things he sees (toys etc) but then also to people.. I think I missed this one in all the reading I did and could only find one reference in a video about it. Thanks
I believe it to be a signal of happiness or contentment and notice it daily among several species of cockatoos. Some do a more rapid-fire beak-click with a bit less movement of the upper and lower beaks.