If you have changed Profile pictures for your users en masse in G Suite, you can simply synchronize the changes to SignatureSatori.
Sidenote: There are several options to upload a profile image for users. This process will pull pictures uploaded by administrators in G Suite or changed by users in their Google profile. However, users can change their image directly in Gmail which will not be reflected.
The procedure is simple. Tick the checkbox for selected users in the Users & Set-up menu and go to the More actions button. Click on Update Profile pictures from Google.
You will see the recapitulation of the operation and be prompted to choose from two synchronization modes.
Update only for users with no Profile picture will attempt to pull pictures only for users with no Profile picture in SignatureSatori (the current profile pictures will not be overwritten).
Update for all selected will synchronize and overwrite all available Profile pictures.
When you choose your preferred option, Confirm the operation. You can monitor the progress at Dashboard.
The Profile picture update is an operation limited by Google and cannot be performed without restrictions. Every account has an option to perform Profile picture update for every user once per day (the number of your users is your available quote.)
While the Profile picture update is being performed, you cannot load Profile picture for users in their individual settings or initiate G Suite Data Sync and vice versa.