How do I remove a floating head avatar in a shared note on Mac?

My husband and I have a shared note. We've each edited it multiple times.

Yesterday, I noticed my avatar floating above a grey arrow near the bottom of the note. If I click it, it shows my full name. That's all it does though, there's no extra menus or anything like that.

Since it was overlapping some of the content I moved it -- by cutting and pasting the content that was below it to a position above it. I can't interact with the thing directly, though if I type on the line it's anchored to it'll shift depending on its perceived position in the line.

I don't need to see my head floating in the note when i'm working on it.

How do I hide or get rid of it?

For that matter what the heck is it?

Image description: a screenshot of the compose area of Notes on the Desktop showing a bunch of empty lines (because you don't need to see that note). On the last line is a circle containing my head floating above a light grey arrow.

[Re-Titled by Moderator]