Seems to be part of the new updates to GPT-4o in ChatGPT (January 29, 2025)

> Increased emoji usage ⬆: GPT-4o is now a bit more enthusiastic in its emoji usage (perhaps particularly so if you use emoji in the conversation ) — let us know what you think.

https://help.openai.com/en/articles/9624314-model-release-no...

Oops. Missed that! That's kind of a relief. I was afraid that it was "remembering" things I was not in control of!

I checked settings, personalization, the memory is empty. I'm using, GPT-4o. I think it's an update, it wasn't like that before.

it uses it for me all the time. Not my favorite