The disgruntled gentleman seated is moaning as a woman is standing on his feet. "I say Missus, if you're anything of a lady you'd stop standing on my feet". The lady gives back an answer that I'd love to have given myself. "Well, If you're anything of a gentleman you'd start standing on 'em yourself".
So even in Edwardian times, it certainly wasn't given than a man would give up his seat for a woman. I don't expect to be given a seat on account of being a woman, but I if a man offers me a seat (which happens occasionally), I'll gladly take it. I don't know if that makes me feeble, but it's nice that some old fashioned courtesies still exist.
However, I know that a number of men say they won't give up their seat, as they're worried that women will take offence. I think this is mainly down to the dilemma of suggesting that you're only giving up your seat because you think the woman's pregnant.
I wonder if the Edwardian postcard approach would work any better than TfL's current Considerate Londoner / Together for London campaign? There is a poster in the series above which has one of the numpty cartoon characters saying "I'll offer that person my seat" and a female numpty saying something like "I'll politely take it".
It's trying to promote a little give and take or to quote the campaign: "A little thought from each of us, makes a big difference for everyone." Maybe they should test a more humorous or blunt standpoint as seen in the postcard, unless that would lead to even more raised tempers!