S2E51- Karl dropping his boxers to expose himself to a naked woman

Im obsessed with this story, but at the same time I am so confused. I imagine Karls apartment is opposite this womans apartment so whilst he's washing up he can see out the window, I'm imagining his sink is directly in front of his window so that he can see out of it and see the naked woman, BUT.

If Karl says that he dropped his boxers to show his arse, did he turn all the way around and almost poke his arse to the window to show the naked woman, but also how low down is his sink for him to do this. Any average sink height goes up to ur hips/belly button, there's just so many details of this story that I need to know.

No offense but how much of an idiot must be of looked when Susan walked in and saw him with his boxers half down with his back to the window and sink just standing there. Someone help, this story has sent me into a state of pure confusion.