I'm not wanting to derail; and much of this thread has been absurdly amusing... but I don't actually see how it is necessarily different. I think we often have an image in our heads of flashers being dirty and nasty - which indeed they are; but when somebody does the same thing in potentially a slightly different context, we can fail to make the obvious connection.
So the man in the park sitting on a bench, wearing the stereotypical long coat with nothing underneath, who knows that there are people around... so he opens his coat and waits for a woman or girl to see him - maybe just sitting there and not approaching or talking to anybody. Is he doing what he is doing for reasons of getting sexual thrills by making people very uncomfortable in having to see what they don't want to? Yes, of course he is.
An OF 'model' - as mentioned above happing several times in just one branch of a supermarket - who is wearing insubstantial/inappropriate clothes that she knows will put her breasts and vulva on clear display to anybody walking past. Is she doing what she is doing for reasons of providing sexual thrills by making people very uncomfortable in having to see what they don't want to? Yes, of course she is.
Yes, most of the people who do this won't be monetising it; but do you really think that there aren't plenty of people out there - men and women - who do get thrills from exhibiting their bodies in public, but maybe deniably so as they are wearing clothes, albeit ones that they know will not properly cover the necessary parts and/or will 'accidentally' fall open?
On a demographic basis, how many people are there in their teens and older who have natural sexual feelings and find that certain behaviours or situations turn them on? Now, how many are there of the same age who genuinely don't realise how clothes need to be worn so that they can function in their basic job of covering the parts that they need to?