The Miracle: 19 Weeks

We're past the 19 week mark - almost half way now. We'll find out if the baby is a boy or girl next week. The baby has been moving a lot this week...I got to feel him for the first time last night! Here is a little more info. on the baby's development:

How your baby's growing: Your baby weighs about 8 1/2 ounces, and he measures 6 inches, head to bottom — about the size of a large heirloom tomato. His arms and legs are in the right proportions to each other and the rest of his body now. His kidneys continue to make urine, and the hair on his scalp is sprouting. This is a crucial time for sensory development: Your baby's brain is designating specialized areas for smell, taste, hearing, vision, and touch. If your baby is a girl, she has an astonishing 6 million eggs in her ovaries. They'll dwindle to fewer than two million by the time she's born

Could someone tell me why they keep comparing the baby's size to some type of fruit or vegetable? It just seems kind of weird to me.