I rarely ever see that. What I do see a lot though is "purse occupying."
This is the practice of a woman placing her oversized purse or large hand bag in the seat next to her. This especially happens on the Metro North commuter trains where women habitually fill up the seat next to them with their purses, coats, umbrellas and whatnot while the men usually stash their bags in the overheads, leaving the seat next to them open. I almost never see a woman put anything in the overhead. When she is shamed into giving up the empty seat, she will take her stuff and transfer it to her lap or on the floor in front of her (and will usually not be happy about it at all).
Well put. Then there’s the whole ritual to it as she lets you know through her movements how unhappy she is to be reminded a person has paid for a ticket and thus entitled to the seat next to her, whereas her high-quality cargo has not.