If you want to be sure, you can just click on the "Open Project" button and select "Team Server" as source. This will open the version that is linked to the team server (If it is not already on your disc it will download it).
The Modeller works always local, you should commit (in tab changes) to bring them to the team server. On the same tab you should update, so you can see changes of your colleques.
Use the main line option, this one is already the working project you have local (incl local changes) and the update.
The team server version will create a new local project main-1, and you wil miss not committed changes.