The bottom line is that the shadow can be three to four times as long as the actual object. All it takes is for the light to be at just the right angle. Low-aiming light gives a long shadow and makes for an illusion of size.
Sometimes people appear to be more than we think. They catch the light just right and cast shadows that surprise us. They do more than expected.
Like when my little student knew all of the right answers today about shapes. His little pebble cast a good long shadow then, and I smiled and told him how proud I was.