Most purposes illuminate the subject of comparison, but a purpose may instead exalt the comparator. The usual order is reversed so that something ordinarily used as the standard is itself likened to the object being praised.
«وَبَدَا الصَّبَاحُ كَأَنَّ غُرَّتَهُ وَجْهُ الْخَلِيفَةِ حِينَ يُمْتَدَحُ»
Morning appeared, as though its bright forehead were the caliph’s face while he was being praised.
Rather than comparing the caliph’s face to daybreak, the verse reverses the direction to exalt the face as the stronger standard of radiance.