It shows a character stripping away their defenses.

Modern audiences are highly sensitive to how consent is portrayed. A storyline that treats the sharing of private images lightly can alienate viewers or readers.

Romantic storylines that include these elements are often attempting to answer a fundamental question:

It mirrors the way real-world couples maintain "the spark" over long distances. Emotional Weight vs. Visual Gratification

It introduces the risk of betrayal or "revenge porn" tropes.

Are they seeking validation? Are they trying to bridge a physical gap?