«كَأَنَّمَا تَبَسَّمَ عَنْ لُؤْلُؤٍ مُنَضَّدٍ أَوْ بَرَدٍ أَوْ أَقَاحٍ»
As though, in smiling, he displayed strung pearls, hailstones, or white blossoms.
Luʾluʾ munaḍḍad means pearls arranged in an orderly row, barad is hail, and aqāḥ evokes white daisy-like flowers. All suggest whiteness, brightness, and the visual appeal of teeth.
The line is a simile: the beloved’s smile is illuminated through several beautiful, concrete comparisons.