The box that its paired with is the "Now Playing" list for the Mini.
Works the same way as between 2 Premieres, you'll see the name of the other unit at the bottom of your list of shows.
-Roamio Pro *Just out of the box!* :D
-Premier Xl4 MOCA bridge w/Slide Pro
-Mini Lifetime MOCA
-Comcast/TiVo Mutant dvrs - RIP
-2x Upgraded Series 2 - Retired