The way Fox News is covering the DNC is actually kinda genius and killing a couple birds (at least) with one stone.
Painting way too rosy a pic of events and speeches for R viewers to think FOX is even remotely a legitimate news source. Real news wouldn't be fawning as much as Fox is (albeit less so than others).
For Dems and independents, it makes "conservatives" look like the adults int he room. The people covering the "news" end of it are being very "fair and balanced" from a lefty's perspective (maybe THEY'RE even thinking Fox is being too kind).
Whatever your world view, Fox is there to provide adequate-ample cognitive dissonance.