That’s the hay loft. Probably more so on older barns, but that’s where the term is from.

You could always write yourself a simple bash clean-up script that kicks off the uninstall and also deleted the profile and anything else you want gone. Not a universal solution, but if you need to do that one thing often enough it would do the trick.

The photosites are continuously reading the light falling on them. When you take a picture, the system takes discreet readings of those values for the length of your shutter speed. However it can only handle the information from a portion of the sensor at a time. So it reads in sequential stripes. The longer the exposure time the more of a chance that the sensor or the subject has moved before the camera reads all the stripes.