'123' is a set of three glasses intended for all sorts of purposes: drinking/toasting, measuring/cooking, stacking/storing. The designer was thinking about these glasses as a set that could satisfy numerous needs throughout the day: maybe for a snack, or enjoying an espresso or a cappuccino or a cup of tea. Maybe even for an aperitif, using the small glass as a peanut bowl.
Later, the water or wine glasses might be used as such, for water or wine, along with a plate of tagliatelle that had been prepared using these same three glasses as measuring cups: flour in the tallest glass (water glass 3dl), four eggs in the medium one (wine glass 2dl) and salt in the small one (liquor glass 1dl).
Set composed of three glasses/measuring cups (1 each - water, wine, liquor glass) in crystalline glass.