pull up any moderately busy picture with more than a trivial amount of objects. pictures of "traffic" or with other similar repetition are great for this demo. pick one specific object (like a specific tire on one car) in the image and write (or say) out all the words youd need to specify that exact object. now take the same image and point at the object with your mouse or circle it with an annotation tool. its often very very hard to describe accurately which object you are talking about, you will often resort to vague "location" words anyway like "on the upper left" that try to define the position in a corse way that requires careful parsing to understand. pointing/annotating is massively superior both in brevity, clarity, and speed.