A tower is long and straight. Ivory is white. The woman's neck is long and straight, and her skin is light in color. (See: [[rc://en/ta/man/jit/figs-simile]])
The woman's eyes are spoken of as if they are clear pools of water. Pools of water are clear and sparkle in the sunlight and so are pleasant to look at. The woman's eyes are clear and sparkle and so are pleasant to look at. This can be stated as a simile. Alternate translation: "your eyes are as clear as the pools in Heshbon" (See: [[rc://en/ta/man/jit/figs-metaphor]] and [[rc://en/ta/man/jit/figs-simile]])
The tower looking is a metonym for people on the tower looking. Alternate translation: "that allows people to look toward Damascus" (See: [[rc://en/ta/man/jit/figs-metonymy]])