A GitHub pull request link in a chat message or document becomes a chip such as PR #4712, and its dot matches the pull request's real state.
The dot colour means: yellow, running; red, failing; green, passing; purple, merged; grey, closed, draft or unknown.
Hover the chip to see a card with the repo and number, title, state, check counts, the names of failed checks, review status, author, when it was updated, and Open on GitHub. It works the same on the web and the Mac.
Where: web and Mac, in chat messages and documents.
Related: Review code in AgentSky, Connect GitHub to a chat.