Direct Mount with top and bottom swing?
"Top swing" versus "bottom swing" is defined by the position of the derailleur cage in relation to the clamp. There are indeed two completely different versions of direct mounts: high direct mount is for bottom swing derailleurs (since the derailleur is below the clamp), and low direct mount is for top swing. The two versions are not compatible.

Bottom swing is in general preferred unless there is a compelling reason to need the more compact size of a top swing; typically this is only the case on full-suspension bikes.

This is not to be confused with "top pull" and "bottom pull", which only reflects the direction of the cable entering the derailleur - from above or below. Both top pull and bottom pull (as well as dual pull which supports either) mechanisms can be found in both types of derailleur mounts.