So, Moonie has been making a low pitched, sort of honking sound lately, at his reflection. I can't tell if it's a mad noise or if it's a happy one. When I know he's angry, he makes a sound more like a chipmunk, and will snap at my hand to try to bite.
Semi-related, I have seen our vet sometimes put his nose right to Moonie's face, I believe because budgies putting their beaks together is a sign of affection. I have started training Moonie to be a snuggler (at least, I think that's what I'm doing) and sometimes I also hold him close to my face, and my nose. He makes this same sound at me, but never tries to bite me. Mostly he sort of gives me little "kisses."
That is one of the many cute sounds budgies make in order to express their affection. In your budgie's case he is being sweet and affectionate towards his reflection and on the second video towards you.
This can also be typically seen between budgie mates.
Your Moonie is a total sweetheart and clearly loves you very much!
RIP sweet Tito (Summer 2008 - January 17th 2013).
You are missed and never will be forgotten.