Qualities perceived by sight include colours (alwān) and shapes (ashkāl). Colour may involve redness shared by a rose and a cheek; shape may involve roundness, length, triangularity, or a distinctive outline.
“A rose is like a cheek in redness.”
“His face is round like the moon.”
The first comparison concerns colour and the second arrangement or shape. Both are visual, but they are not the same visual characteristic. Naming the precise aspect is often more informative than vaguely calling everything “beauty.”