The screen-signature POS terminals I've seen almost always have another screen showing a list of purchases being made. The only exception I can remember is very old pharmacies. In newer pharmacies, the list is on the signature screen.
Interesting. Everywhere I've been recently (mostly west coast, I'll admit), the grocery stories have the biggest tally screens. And at the bottom the biggest line is how much you "saved" by shopping there. (Yeah, right.)