TL;DR: Should be OK.
Warning! Wall-of-text explaining why it should be OK.
Usage of Logos fall more under the “Branding” side of the law than on the “Copyright” side of the law.
If you’re referring to this point from this site’s T&C…
the downloading, copying and use of the Content will not infringe the proprietary rights, including but not limited to the copyright, patent, trademark or trade secret rights, of any third party;
Combined with this from the FAQ
You may not post anything digital that belongs to someone else without permission. You may not post descriptions of, links to, or methods for stealing someone’s intellectual property (software, video, audio, images), or for breaking any other law.
…the intent is to prevent piracy… i.e. don’t upload pirated material or links to pirated material.
e.g. posting a movie-poster = OK, positing that movie = NOT OK.
Pretty much all endorsed promotional material is public domain and distinct from the IP itself. General rule of thumb - if it is behind a pay-wall, then you can’t share. Additionally, if you do share something, give attribution if it is not clear. (e.g. if I cropped out the bottom of a movie-poster and posted it and said “hey guys! look what I made!” that would be a clear violation.)
WRT Logos, a company can only really come after you if you are grossly misrepresenting them or pretending to be them… In something that is clearly a derivative art work, they’ll have a harder time. Fan-Art and derivative works are generally protected provided you’re not attempting to make money off of it where the derived portion constitutes the majority of the work.
(Not a Lawyer, just attended a talk given by a lawyer on this type of topic quite long ago, so if there are any Lawyers who can back this up or refute it that would be great)
EDIT: added TL;DR and some clarity. Sorry for wall of text.
