Git diff|status against remote repo

Hi.

I am far from being a pro in git. There is something I do not understand.

This is my git config:
[core]
         repositoryformatversion = 0
         filemode = true
         bare = false
         logallrefupdates = true
[remote "origin"]
         url = ssh://git@192.168.2.2:/home/git/PROJECT.git
         fetch = +refs/heads/*:refs/remotes/origin/*
[branch "master"]
         remote = origin
         merge = refs/heads/master
[branch "develop"]
         remote = origin
         merge = refs/heads/develop

I have a local repo called "develop" also on each involved dev machine.

Developer A has made changes on nearly each file of the project by changing the namespace and locally commited those changes to his local branch "develop". After that he did a git push.

On a not involved machine M I did a git clone ssh://git@192.168.2.2:/home/git/PROJECT.git and after that I did a "git checkout develop" which was followed by a message like "Branch develop is following remote branch develop from origin". I can see all the changes Developer A has made.

On my machine DEV I am on my local branch develop. Since I did not pull or merge from origin already, I am not able to see any of those changes developer A has made. So far so good. But I would expect, that git status (which results in "On branch develop. Your branch is up to date with origin/develop) or "git diff origin/develop develop" or "git diff origin/develop...develop" (both no output at all) would give me a hint that I am x commits behind origin/master or (git diff) will show me the changes Developer A committed to the Repro. But nothing...

What am I doing wrong?

Thanks, Steffi