Translation:The girl is wearing pants, a black top and shoes.
The translation is very loose. Most literally, the Russian means "On the girl are ...." It can also be translated more closely "The girl has on ...."
The standard Russian for "The girl is wearing (wears) pants" is "Девушка носит брюки".
Duo should accept "is wearing" here, but it should not reject other translations that a better (closer to) the Russian sentence.
Yes, "she is wearing" means she has them on at this moment, while if that is how she dresses habitually or at least frequently it should be "she wears". I would have thought "носит" could mean either. I guess that's incorrect. So to translate "девушка носит брюки" as "the girl is wearing pants" is incorrect.
"носит" describes her personal preferences, not the way she is dressed now. I wouldn't say "Труп носит" unless it is a walking zombie.
If you're talking about a murder investigation, you say "труп был одет в чёрный костюм" or "на трупе был чёрный костюм". "носил" isn't appropriate here since dead beings cannot "носить" (which is undoubtedly connected with нести́/to bear, carry) clothes in Russian.
No, I haven't checked alternative translations yet.
What kinds of garments are encompassed in кофточка? "top" I understand to be pretty general. The hint I can see is "blouse." Reverso gives sweater, camisole, and jacket, which seems a somewhat implausibly broad range.
The Google Image results I get are mostly loosely woven sweaters, all worn by women.