The title almost sounds like that they have a meaningful fingerprint ready to open her iPhone... Was that the case? Or do they have a somewhat accurate partial fingerprint? I failed to find recoding of the presentation.
However, they are showing their attack working on a Macbook Pro with touchid, which uses this sort of reader. So it's easier to fake in practice than it is in theory. Whatever material you lift the print off of should have to mimic the capacitive behavior of the finger and this looks like it busts Apple's claim that it can read the lower layers (or it tells us their default sensitivity is set too low for convenience)