On reflection I think she had thought that one queues at a bar, and I wonder if she had been standing for some time behind a group of people at some distance from the bar, thinking she was at the back of a very slow queue. Seeing me walk up to the empty bar (ETA - I mean here 'the empty part of the bar') and wait to be noticed by the bar staff, made her think that I was pushing in. So, in other words, she was in an environment where she didn't understand the norms of 'how to behave at a bar'. That's not her fault, though I do think it is a particularly upper-crust British attitude to go into an environment that you aren't familiar with and get angry with people for not being like you (the British have certainly been criticised for doing that to 'foreigners' even in their own countries).
Anyway, this memory was stimulated by this BBC report about how to get served at bars.
Britain may be a nation of queuers, but the thought of lining up in an orderly fashion at a bar is enough to turn many a drinker's beer flat. But that's what patrons of busy town centre pubs in Oldham may find themselves doing if plans for post office-style queues go ahead to deter trouble.
Hmm. I do think British pubs are understaffed compared to American and European bars. In Europe (this is how it seems to me) there's less of a tendency to pare overheads to the bone, so there are plenty of staff, and in the US wait staff are badly underpaid but at least get decent tips so there tend to be as many as the custom will stand (this is just what I've been told by various people).