YES I AM A VIOLET EVERGARDEN FAN!

For those of you who don't know what it is, here is the description i found

Violet Evergarden. In the aftermath of a great war, Violet Evergarden, a young mostly emotionless female ex-soldier, gets a job at a writers' agency and goes on assignments to create letters that can connect people.

Anyway, this has been haunting me ever since I finished the series

who was at the door at the last scene?!