Trans individuals in both binary directions who haven't had certain medical interventions yet and don't have access to purpose designed gender presentation gear such as packers or breast forms, will frequently use socks rolled up in some way to simulate boobs or a bulge. Sometimes, these items, either purpose designed ones or versions improvised out of socks, will get left out in a shared bathroom in a moment of carelessness or distraction, and housemates might ask about them, which can be embarrassing.