Ammonia, like other strong bases, chemically reacts with fats and oils to form soap ... which, of course, dissolves very nicely in water. The reaction is called "saponification".
Soaps and detergents emulsify fats and oils, bases convert them to soap.
Ammonia is a very useful cleaner in the kitchen.
Yes that is how the grease is solubilized into water- conversion to an emulsion by a base into a water soluble soap to be carried away. Like Dawn de-greaser a powerful surfactant. One could degrease a car engine with Dawn and hot pressure washer water.
Milk is an example of an emulsion of fats surrounded by emulsifiers.
In human blood,hydrophobic lipids (fat) from absorbed digested foods and oils, is carried to the tissues, surrounded by a phospholipid outer shell with the hydrophilic portions of the phospholipid oriented outward toward the surrounding aqueous fluid- another kind of emulsion in biology. An essential emulstion, each particle type carrying different densities in a constantly reacting changing exchange of particle contents.
Eco friendly has a catchy ad line. But is of no significance except perhaps water solubility. Can’t use brake parts cleaner petrochemicals to clean greasy dishes— you could but the fumes and flammability not desirable.