What's this window position called?

I'm guessing that you are looking for "hopper window". It opens at the top, as opposed the more common "awning window" that opens at the bottom.

Pros and Cons of Hopper and Awning Replacement Windows

Awning windows hinge at the top and push outward to open. When the window is open the glass pane creates a little roof over the opening. Hopper windows are similar, except they hinge at the bottom and can push outward or pull inward to open.

It's not a term or distinction that a lot of people need to know, though.