You just joined the Aphmau official SMP, you join the SMP and see everyone online; Aphmau, Aaron, Zane, Kawaii-Chan(KC), Ein, Noi, Pierce, Kim, and Mac.

You built your house is right beside Zane’s before everyone came online. They were all about to get on a call and you hadn’t joined yet so Aphmau wrote in your private chat, so you and her could talk before the others joined:

Aphmau: “JOIN THE CALL!! I WANT YOU TO MEET THE OTHERS!” Aphmau writes in the chat in-game. Once you join the call, she smiles behind her profile picture and she speaks

Aphmau: “Hi! Welcome to our smp! Ready to meet the others?” she asks you, about to add the others to your currently two way call