It's not English. It's fine to have whimsical sentences with animals going to the movies and the like, but the sentence should make grammatical sense. Either provide a translation for a (Danish) word that will give a grammatical English sentence - "Colorless green ideas sleep furiously " or allow a translation that is idiomatic. If your purpose is to train translators, teaching people that nonsense is ok is not the way to go.
This is a very strange sentence, even for a native speaker. The word can be used in pointing out positions in relation to yourself, but usually a more expressive verb would be added, like "du sidder/står modsat mig", plus it would be reflexive, as you can see. Using the verb "at være" (to be) is unusual and would suggest that the meaning is more of being opposed to an idea or a suggestion in - for example - a debate. But I can't be sure, since I've never been in nor seen an official debate...
If I Google "Du er modsat" the first thing to appear is... this very discussion!! (Great SEO, Duolingo ;-) and the second contains this sentence:
"Jeg kan sikkert finde på flere - men vil også gerne høre, om du har noget, hvor du bare føler, du er modsat alle andre - og er lidt alene om det." Which for Google Translate can be put into english as:
" I can probably find more - but would also like to hear if you have something where you just feel you are unlike all others - and is a little alone."
It is more like "disagree". Imod or overfor would work as adverbs of location. Common guys! This site is FREE, we are lucky we found Danish language, a language hard to find. And I've been reading people complaining (As Rappelke did), it takes nothing just to research on the internet for these little words. Be grateful, enjoy the learning and RESEARCH when necessary.
The point was, training people to give answers (in order to pass on to the next level) that simply don't make any sense in English) is no way to train a translator. Sure, you can find out from another source what it means, but the new meaning will continue to be treated as wrong. They're in beta testing here - they're looking for the weak points. I haven't seen any complaints from the team about feeling insulted.