Windy doesn't care, he walks over looks and moves along.
Willow is the mirror lover in my house, he serenades himself.. but he's never been aggressive he doesn't spend all day at the little mirror he just wanders over sings to it, and hopes, well I'm not sure what he hopes for. I think it's prolly dirty though cause it's the same song he sings on his wubby *cough*
I had a big mirror on my dresser upstairs I had to take down though because he couldn't get over his excitement/obsession with that one. He'd walk back and forth just a singing his heart out. Since that room is where I take each bird for quality alone time, no cats, just one bird and myself, it just got annoying for me really. He'd just keep flying back to it... he kept looking for it for awhile but seems to have forgotten it now.
If I ever thought it was upsetting to him, I'd take it out. I think having Windy with him helps keep him from going overboard.
He does "love on his wubby" though .
Not all the time. Just once in awhile.. I'll hear the same song he sings in the mirror and notice he's tail feathers are, well you can imagine.
I guess as long as he's not aggressive or upset about it though, just let him be. That's what I've read anyway.