I suspect this advert has caused so much comment because 'uptight nervy cardigan woman' speaks to many people much more than 'cool lipstick girl.' We are not meant to empathize with the crisp eating frump but we do.
Shes sitting there, hair scraped up, old cardie, no time for lipstick, eating a bag of crisps because she hasn't had time for lunch = limited time for self care , the bag on her lap symbolic of all the burdens shes juggling in her own life, physical, mental, financial, caring. Her defensive body posture, trying not to draw attention to herself as a lone woman on a near deserted train platform, her face worried - why? we don't know anything about her, who she is, where shes traveling to or from, what emotions or situations shes balancing, what memories or instincts the sight of the man who is behaving erratically awaken in her.
(It would be interesting to find out the instinctive response people have to that character - is it sympathy with his vulnerability or wariness over his disturbed emotional state? - I wonder if they asked this while doing market research on their ad?)
She sees him, recognizes his distress because she is fundamentally empathic and weighs up what she can do. Her instinct is to help, but she also is balancing that with her own safety and all the other responsibilities she has on her shoulders - what happens if she puts herself in danger and he reacts with aggression? what happens if she ends up engaged in something prolonged and no one picks the kids up from school? what support has she to give at the moment when shes in the middle of her own emotional crisis? - and shes understandably wary of helping. She weighs it up - of course 'someone should do something' but feels that she cannot be that 'someone' in this situation.
I am sure this is the 'bystander effect' they want to tackle but this advert it focuses on the wrong problem - and its here that the add shifts the story, and segues into a weird world where she overcomes all that and puts all other considerations out of her head to approach a distressed stranger with a lame line that could certainly be mistaken as sexual interest by the wrong disturbed person, - so completely misses the mark.
The barriers that prevent her intervening are not so much fear of getting it wrong as fear of what might happen next and the potential cost and harm to her - and this advert doesn't recognize any of that. It would be good if they showed an action she could take to help without putting herself in danger eg contact a staff member? or perhaps she could start an action while protecting herself - eg approach him as part of a group/ pair, and use something better as an intro line like - do you know if this is the train til x? that could not be misconstrued.
I wonder if they considered or have made the same advert with a man approaching another man? or if they thought that would be too unrealistic to expect that level of empathy and engagement with a stranger - or perhaps they recognized that many men would with good justification fear violence from an unsolicited approach in the situation