eurgrus,
I tried the 'import screen.png', and selected a portion of my desktop. When I tried opening with Gimp. It says the PNG file specifies an offset that caused the layer to be positioned outside the image. I retried while grabbing more of the screen or even capturing to the top left corner. That worked somewhat.
It seems if you call the file a .png one cannot select a small section on the top right of the desktop, you will get the offset error message, but if you specify the filename to have a .jpg extension, it works.

Thanks. This import statement works good.