The plaintiff, after being abandoned by Sarah at the last minute, deserves to enjoy her memories without Sarah's intrusion. Sarah's request is not only insensitive but also presumptuous, considering she made no contribution to the trip. It's about respect for the plaintiff's experience, not pettiness.
The plaintiff is being unreasonable by gatekeeping experiences. Sarah's request, though perhaps ill-timed, stems from genuine curiosity and a desire to share in a trip she initially planned to take. Denying her the pictures smacks of spitefulness and an attempt to punish Sarah for changing her mind, which she is entitled to do.
Sarah's last-minute cancellation was inconsiderate, leaving the plaintiff in a lurch. However, the plaintiff's decision to withhold photos appears vindictive, especially since Sarah's request is merely for personal viewing. The plaintiff is not obligated to provide the photos, but denying them only serves to escalate the conflict unnecessarily. Grow up.