Maqādīr concerns quantities and extensions, such as the length of a line, the extent of a surface, or the dimensions of a body. Such properties may be used as visible points of resemblance.
Shape concerns the configuration of boundaries and parts. Magnitude concerns length, breadth, or volume. Two objects can share a round outline while differing greatly in size.
“Two minarets have the same height” may compare their magnitude; “two bows have a similar curve” emphasizes form. It is incomplete to label both merely “visual likeness” without determining the actual intended feature.