It is not necessarily a natural connection for Data to make, but he has done enough research on symbolism in certain forms of art and literature that the possible association does occur to him. He gasps lightly at the feeling.

His eyes are glued to her mouth. He had not realized that there were further connections to be made between his emotional programming and his optical sensors, but they are there now, and they are quite obvious. It is an oddly pleasant (oddly stimulating) image, watching her tongue and lips move in that way.

He shifts forward on the bed, closer to her. His other hand reaches up to stroke loose strands of her hair, eventually burying itself in her curls. His breath is still uneven, and his eyes are wide, focused intently on the beautiful human in front of him.