You can customize the image your buyers will see once they log in.
Go to Settings -> Branding
Upload the Buyers Home Screen image as indicated in the profile requirements (1920x1080 pixels in size, Jpg, Gif or Png)
Upload My logo to customize the logo shown in the top left corner of the Buyers home screen as indicated in the requirements (458 x 167 pixels in size, Jpg, Gif or Png)
When your buyers login they will see the image you uploaded: