Why is there a terminal e for "Très différente"?
There is only a terminal e when the thing that is being described is feminine. French adjectives are modified based on the gender of the noun that they are applied to.
For example - Ton manteau est très différent. (Your coat is very different). Ta jupe est très différente. (Your skirt is very different).
I thought that might be the case, but Duolingo insisted on the "e" despite no context being given for those two words.
Especially in the early phase of the course I noticed a marked preference for feminine endings in phrases where masc and fem are homophone as in plural often happens.
@Gersois, is the question translating from the spoken French? Because if so, you should be able to hear the "t" sound if it's "différente" and no "t" if it's "différent".