My favorite moment in this episode is when Dawn gives Buffy the picture of them framed by seashells they picked on the beach.
It is so neat to see everyone's reaction to this sweet, sentimental gift about an event THAT NEVER HAPPENED!
It's a perfect gift from a loved one but everyone, including the viewer, is made uncomfortable by the secret knowledge that only Dawn still believes in her past.
It makes the destruction of her imaginary journals later even more poignant.
A very low-key, underplayed but exceptional moment.