GitHub Pull Request merge commands

[Florian Lindner <mailinglists@xgm.de>]

Hello,

GitHub proposes these commands to merge a pull requests (explanations from 
me, to make sure I got it correctly)

# Basically branch develop to davidsblom-develop
git checkout -b davidsblom-develop develop

# Pull in foreign repos commits from foreign develop branch.
git pull git://github.com/davidsblom/precice.git develop

# Edit and merge the changes to the main repos develop branch
git checkout develop
git merge --no-ff davidsblom-develop
git push origin develop

My question is, if davidsblom make further commits to his develop branch 
(after the pull request was issued) aren't these commits also included in 
the pull and therefore in the merge? If yes, isn't the idea to merge just 
the changes that the pull request was about? If not, why? ;-)

Thanks,
Florian