To some extent, yes. Mine never get really, really bare, though, just thin. Mainly they sit in the next box 24/7, getting up usually only once a day for a few minutes to eat, drink, poop a huge broody poop, and sometimes get a little exercise like a fast dust bath or a little pecking and scratching. Typically they flatten out on the nest, as if to cover a bunch of eggs. Also, they typically growl and fluff up if you get near the nest, and peck at you like mad if you reach in. My best broody never growled or pecked at me but she was my pet, and she sat for weeks and weeks on nothing, then did a great job of mothering when I bought her a few chicks and slipped them under her.
If she went back to the nest in a few minutes after you put her out, she may well be broody. But one way to break a broody is take them off the nest and make them go run around and be a chicken. I've done this with success a couple of times, but usually I have to take them off a couple of times a day, or more over several days. I had one who persisted in being broody for months even though I did this daily.
Broodies never poop the nest. Chickens who just like to sleep in nests always do if they're there long enough.
Of course all rules have exceptions, but I've never seen one with the pooping the nest thing.