Glass-top freezers combine chest-freezer storage with display. The lids are usually double or triple glazed and slide sideways, so a customer can open a small section rather than the whole top. Curved-glass versions give a wider view of the contents; flat-glass versions are simpler and stack more neatly in a row.
Glass lets more heat in than a foam lid, and in a non-air-conditioned shop it can also collect condensation. Good units manage this with low-emissivity or heated glass and adequate cooling capacity. Users help by keeping lids closed, keeping the unit out of direct sun, and stocking below the load line so cold air can circulate across the top layer.
A sweet shop in Kolkata selling kulfi, ice cream and frozen desserts in summer might place a curved glass-top near the entrance. Shoppers browse the flavours through the glass and slide open only the section they want, keeping the rest of the stock cold.