What's the actual difference between the "Guest Link" and the "Full Access Link"?

They open two completely different experiences. The Guest Link is the private, selfie-based flow: guests register, upload a selfie, and see only their own matched photos. The Full Access Link is the master key — it contains a secret token and reveals the entire album with no registration, so whoever holds it can see and download everything. You'd share the full access link only with people you trust completely: the couple, an event organizer, a videographer who needs the whole set. Snaptide itself labels it "share only with trusted hosts or organizers."