First, if you're a believer, you're called to think about this. It's a picture of our dependence on what God has revealed. Read 1 Pe 2.1-3.
Secondly, when a child is born, the extent of their vision is usually about 18 inches or so. This happens to be about the distance from the mother's breast to her face. Newborns are hardwired for intimate dependence and not mere provision from a distance. This is explicitly the product of nothingness, chaos, chance, random mutations over billions of years, and people with real emotions surviving because they're better than others [like Hitler]. Or... even as Darwin suggets ["To suppose that the eye... could have been formed by natural selection, seems, I freely confess, absurd in the highest degree."], there is likely another Source for its intricate design and beauty.
Lastly, [and I'm sure I'll miss some miniscule biological detail here], when a baby first latches on to breastfeed, he/she exchanges fluid with mama through the breast. This newborn spit tells mama's body what the appropriate balance of nutrients should be for that child. Thus, mama's body makes a special batch of milk for her kid that wouldn't be the best for any other kid.
Again, because we worship the scientific method and human reason, this is easily explainable as surviving to be fit. But if you actually think about it, it's humans needing humans to remind humans that we need something other than humans. Any school of thought demands that we need external means to survive. But surely that cannot apply spiritually because spirituality is a product of the human psyche to pacify humanity so that they can get through tough times. It is "the opiate of the masses" [Marx]. Or... There is a good and wise God who sent Jesus [who went through more crap on earth than you'll ever go through] in order to make whole those who trust Him.
This is how theological neatniks think about breastfeeding. Maybe this is also what Jesus had in mind when he said, "Consider the lilies." I sure hope so.