Reverse mirror basically means a game is on one of two stations (ABC or ESPN2 in this case). There's another game at the same time that is also being reverse mirrored (The Neb. game in this case). In a part of the country, The Canes game is on ABC (and the Nebraska game on ESPN2) . For the rest of the country, the Canes game is on ESPN2 (and the Nebraska game is on ABC).
This game is technically not a full reverse mirror, because the Canes game isn't on in half of Montana for some reason. It's only on ESPN3 for people there. But it is for the rest of the country.
As peeps have said, the Miami game is on ESPN2 out here in California.