I was googling about of Gitlab on Eclipse about what means this image:
Secondary click doesn't say nothing about this.
I need to be secure about the changes using Eclipse
At least if you have some inditication, when the Mouse is over the package or folder selected the Eclipse must to show a caption or message indicating what is recommendation.
This arrow indicates that you have committed once (therefore the one), but you haven't pushed the changes to your remote
yet. The remote
would be in your case Gitlab.
EGit/User Guide - Label Decorations:
āN ā The local branch has N commits that are not yet on the remote-tracking branch. This can be read as "N commits to push".