Where does the guest see my brand while they're browsing?

All over, if you've set it up. The album page shows your studio name and "Photography by [You]" with a link to your profile, the guest access page is branded with your studio, and your logo sits on the album. If you've gone the white-label route, the whole experience runs under your own domain and your own email — guests would have to look hard to find any Snaptide mention at all. For most photographers, the standard branding already makes the delivery feel like part of their own service.