Log in to your Admin Control Panel.
Under Location Settings (far left column), go to Photo Manager
The purpose of the Photo Manager is to let you:
Store Photo: Upload an image of your storefront.
NOTE: This file should be no bigger than 88 x 92 pixels
Create a RECEIPT LOGO: Upload an image that "prints" on the customer receipt.
Gallery Photos: Upload images to be viewed in a Photo Gallery on your main Storefront screen.
NOTE: These files should be no bigger than 400 x 400 pixels
Drive: Save files to use on the site by uploading here and then opening in another browser tab to get and use the URL link for that photo.