How can I change what is shown under the Contact tab on the Account Profile page?

If you have access to the Admin>General page, you can configure what is shown under the Account profile's Contact tab. This can be done by navigating to Admin>General and clicking on "Customize Fields" next to the "Contact Tab Key Details" page as shown below:

This should bring up the "Customize Contact Tab Fields" modal. You can then proceed with selecting the fields you wish to see:

Once the field is selected click “Save” and you should now be able to see the selected value on the Contact tab: