Clothing is mainly ingroup out group social signaling.

Women signal sexual availability with they clothes they wear.

Thanks to tinder, she is certain she is not going to meet a sexual partner in person. They will all look at her profile picture online.

So part of the shitty dress standard is to discourage men from talking to her and giving her 'the ick'; and part of it is to signal to other women (and fags) what social group she is a member of.

She has no interest in being seen as cute, attractive or feminine. So she dresses in baggy, mannish clothing.