Screen shots are a very useful way of saving the PFD/MFD display and they produce better results than photos. The screen shots are saved to the SD card but, for some reason, Garmin uses what seems to be a totally random file naming system that allows previously stored screen shots to be overwritten by later files using the same name.

If you value your screen shots it's a good idea to copy them off the SD card and save them elsewhere. Be careful not to let duplicate file names replace ones you have already saved.