I don't agree. I think she is a female and is herself, not a body double. The video is not comms, but simply a clip (I believe) from her television series called The Morning Show where she plays a popular morning talk show host who is very narcissistic and neurotic.

The clip is from a scene at the end of the first season where her character experiences something traumatic and her on-air co-host suffers a terrible fate, while she survives. She is speaking to her beloved viewers who adore her, but she is feeling responsible and guilty for some of the events that transpired.

So I'm thinking this is a dramatic scene from that tv show, and not just Jennifer Anniston talking to herself on Instagram or something.