ChatGPT Work in the ChatGPT web and mobile app experience is very different.
If you like, you can think of it as a cloud-hosted version of Codex that's skinned to look more like consumer ChatGPT.
It even shares the same login state and conversation history with /resume, at least when running it in a "project" (which seems to largely map to a directory/repo, at least the one selected as "primary"?)