It's a specific liquid scanner that's done on bottles that have been pulled aside for extra scanning (at least, that's what Frankfurt was doing a couple weeks ago)

As far as I know, it's not. You're now specifically told to not take liquid out of your luggage.

At least that was the situation when I flew out of London Gatwick last time - they had people going up and down before the scanners admonishing people to leave everything in their bags to avoid delay.