oh YES YES YES! i love this idea and it is another very real type of viewpoint that I have come across in department stores many times.
the great thing about your suggestion is that you can masterbate behind some clothes and you'll only be visible from her viewpoint from like the neck on up. it's perfect cover cuz she will not see you masterbating and might only find it strange that you are just looking at her so fondly when she catches you.
on the downside of this, there is the possibility that other women in the store who are positioned at different angles from you may not have the clothing in their view to block your crotch area and they will immediately wonder what the hell is going on, and possibly inform the woman of what you are doing as soon as they figure out who ur lookin at.
so my advice to the foot pervs out there in department stores over this holiday season is to make sure to look around and verify the coast is clear before ya start wackin it. and also of importance is to make sure you also look around periodically to make sure no customers have also walked into the area in case you are taking too long to shoot your load.
the funny part about all this is the clothing that you will probably dump your load on LOL! imagine some husband buying his wife a dress for xmas later and he happens to grab the one in her size and has it gift wrapped at the store and his wife opens it up on xmas and tries it on and that is when they see steve-o's big crusty stain on the dress LOL! the lady will immediately accuse her hubby of being a shoe perv perhaps
...and naturally, he will have a dumb look on his face and try to deny it, Hee Hee!