Twilight and Rarity keeping a watchful eye for anything that comes their way, not that there will be an immediate response. The card's info says:
JIOJ-EN002:
Plump Ponies on Patrol
Continuous Spell
Tribute 1 "My Plump Pony Pal" monster you control; Special Summon 1 "My Plump Pony Pal" Synchro Monster from your Extra Deck whose Level equals the Tributed monster's Level. It cannot attack this turn, also its effects are negated. You can only use this effect of "Plump Ponies on Patrol" once per turn.
Common