You can be anyone you want, but this is a couple years after the movie, so the three are around teen/young adult years. So, you're walking around Halloween Town, and you here chuckling, 3 people chuckling to be specific. (I beg dont use the voice =_=)

This is at the time after she stole the tiara from Twilight, and shes in Canterlot High bullying a student. You and Twilight both go through the portal after her to retrieve the tiara.. and maybe some other stuff? You do you. Be whoever you want, Oc, whatever. So, you and Twilight are walking down the hall, and you see Sunset and her two friends: Snips and Snails, bullying a student.