What use do? It certainly does not have to buy a view of intensive use, cost (approximately 30 cents per photo) is too expensive. Rather see this little printer as a backup solution for developing one or another photo needed at the time. I also think that in the menu you can choose the ID photo format.
Note that the quality is really sensational for such a small device. It is difficult to see the difference between a picture of the Selphy and that of a terminal. I'm not an expert, but I find those of the Selphy less vague and more colorful. Now this surely also depends on the terminal.
Warning: As other reviews mention, it is imperative to purchase more paper and cartridge on your first purchase. The unit is supplied without unfortunately.