Everything so far has happened on one machine.
Remote
Also called origin
Another copy of the repository, usually on a server, which yours knows by name. The usual name is origin. Your machine also keeps its last-known note of where the server's branches were, called origin/main.
Work you haven't sent to a remote exists on one disk only. And origin/main is a memory, not a fact: it was true the last time you checked with the server. An agent reasoning about what is on the server from an out-of-date origin/main can be confidently wrong, so have it fetch first.
Say it to your agent
“Run git fetch origin, then git log --oneline main..origin/main to see what the server has that we don't. Tell me what you find before you do anything about it.”