TS: Play a wicked trumpet solo to unwind a little.
Ahem. Moving on! Pinkie explained some of how to use this machine last night, although not all of it, because she didn't like spoiling surprises. Rainbow wasn't listening, of course, and Applejack looked to you like she wasn't feeling too well, but you and Rarity paid quite close attention. Fluttershy mostly looked frightened.
In any case, she said that the "groovebuttons" are those large parallelograms on the right side, and they're tied to the two "modes" of the console: the top one triggers STARE MODE, which lets you check in on your friends, and the bottom one triggers VOICE MODE, which lets you chat with them. The bottom row of buttons, with your cutie marks, obviously let you choose which pony to check on or talk to, although you don't think Pinkie mentioned why they would be glowing. Your own button is tied to various personal stuff.
"Groovebuttons?" you remember asking her when she stopped to take a breath.
She bounced happily. "Yeah! Because they're groovy!"
Twilight with a trumpet on her head still from Rhythm is Magic: Peckish Pony 2.