The Credit Score Graphic formula image field is not only shown when the record is being viewed or edited but can also be seen when you include the field in a list view.
Formula fields containing an image can also be sorted on in the list view.
You can see what this looks like within a list view when the list of account records is set with various scores on the CREDIT SCORE GRAPHIC column, as shown in the following screenshot:
Accessing Google Charts requires sending data from Salesforce over the internet so it is not secure. You should ensure only non-sensitive data is being sent.