Characters
What are you supposed to be, some kind of cosmonaut?
— Hotel guest ‧ Ghostbusters

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker asks whether the person addressed is supposed to be a cosmonaut. The phrase some kind of gives the question an uncertain, potentially dismissive edge. It raises the possibility of a space traveller without establishing why that comparison has come to mind.
Context reviewed