يَزِيدُكَ وَجْهُهُ حُسْنًا إِذَا مَا زِدْتَهُ نَظَرًا
The face appears increasingly beautiful to you the more attentively you look at it.
The line connects an increase of perceived beauty with an increase in the observer's attention. Its discussion distinguishes fresh awareness of subtle features from an actual alteration in the face's external beauty.
Reflective awareness of successive fine points is not identical to a claim that the external object has physically acquired new beauty. The rhetorical attribution must be assessed through intention and indication.