Bird looks like she's going to vomit?

[halogen]

My cockatiel Arya occasionally does this. She'll open her beak and stretch out her neck multiple times while she's sitting around. If I had to describe it, it looks as if she wants to vomit. But she doesn't. She seems calm when she does this...is it a sign of some emotion? Or is she just shifting things around in her crop? She's aged 17 weeks. Jut wondering if she's okay.

 

[U2gal]

Sounds like she is yawning or just stretching out her crop. My guys do this after eating a lot.