Both good points, mumsy & marmark, though why is this kind of attention seeking, if that's what it is, seen as silly, whereas it's perfectly allright for people to use other, "approved" kinds of self-promotion for their work? Artists, food advertisers, etc, are classic "attention seekers" by the reckoning of judging publicity stunts to be automatically silly.
I tend to agree, mumsyface. Some people have odd clothing and footwear choices but most people make sensible choices based on what they need to be doing and what they find comfortable. Also what's in fashion. You don't see many people in long dresses working in fields.
When I was working as a librarian in university libraries I always wore trousers because I cycled five miles to work in all weathers (except deep snow, which was rare). Someone once said that my style was "smart casual". When I was teaching in schools, both here and in Thailand, my choice of clothes was adapted for the environment and climate but not, essentially, different. Nor is it now when most of my work is physical and outside, often in muddy conditions.
I think that some people naturally look smarter than others because if I wear a structured jacket I look and feel overdressed, whereas some people just look casual in the same sort of garment. I think it's partly to do with one's general appearance: some people simply have a neater appearance, whatever they're wearing, than others. That's not a judgmental comment, just an observation.