Your team/workspace can be personalized by adding a photo to the dashboard profile. This gives your workspace more of an identity and makes it easy to identify if you are part of multiple teams/workspaces.
Sign in to your Calendar account and go to your settings found on the lower right side of your screen (person and cog icon).
Click on settings to open up your settings menu.
From there, click on the large circle that represents your team/workspace. It will have the initials of the workspace name.
Once you click on the circle, a pop-up window will appear that lets you choose a photo file and then save it to your workspace profile.
You will then see your circle transform from letters to the photo you have selected.