Agreed.

You get up to the edge of the bar/frame. The person in front gets the space from the bar forward.

As an aside, I have fond memories of a flight MSP-EWR in early 2001 where ~50 kids from a school group were on board connecting onward to Europe. Many of them sat down and then put their bags under their seat, just like at their desks in the classroom, rather than under the seat in front. Of course, one of them was in front of me and we had to sort that out (all friendly). The chaperones laughed almost as much as I did about it.