وَعَيْنَانِ كَالْمَاوِيَّتَيْنِ اسْتَكَنَّتَا
بِكَهْفَيْ حِجَاجَيْ صَخْرَةٍ قَلْتِ مَوْرِدِ
Her two eyes are like two mirrors, sheltered in deep sockets pictured as caves in a rock with a hollow where water collects.
Al-māwiyyatayn is a dual expression for mirrors, emphasizing clarity and shine. Istakannatā suggests being sheltered within a protected recess, and so develops the impression of deeply placed eyes.
Kahfay ḥijā jay joins the image of caves with the bony margins around the eyes. The verse therefore combines the brightness of the eyes with their protected position, not merely comparing two shiny objects.