Calling attention to it reminds me that I didn't finish the phrase! I think I got distracted again just thinking about it! Dangit!
should have read more like:

The complex interplay of her low top with the sunlight slanting through the roof is what gave me pause.

or if one wanted to leave out the sunlight, one would have to change interplay to something else (since I think of interplay requiring two subjects).

The complex choreography of her low top.
The complex maneuvers of her low top.

Or for some real fun,
the complicated gamboling behind her low top...