"Rarity! Great timing. I've almost got this receiver working," Lyra says, as she fiddles with the device she's holding. "I need some help parsing the signals. If you could just lend a hand, I mean hoof - "
"Lyra, darling. When are you going to let this go? Humans don't exist."
"Sure they do! I just need to figure out the right pattern. Then you'll see."
Sighing, Rarity starts looking the receiver. "Fine. How does this work?"
"Well, I'm not sure. All I've figured out so far is that 'Live long and prosper' goes to 6 if it's light-skinned and 17 if it isn't."
Hints are available here.