One way to express friendliness or politeness in Mexican Spanish is to add diminutive suffixes to words. For instance, someone giving directions might tell you to pass the parquecito — the “little park” — even if the park isn’t little. At the cafe, someone might ask for a cafecito, or “little coffee,” even if he wants a large. This makes sense to me.
Other times, the habit makes less sense. You come back from the beach and a friend tells you that you are quemadito — a little burnt — even if your skin is glowing red. When you order a juice at the corner store, the cashier asks you if you want el chico o el grandecito? — the little one or the nice little big one?