Drink is the only upscale bar I've been to that actually spends a good amount of effort into making their ice cubes. They were perfectly clear and the bartenders spend a good 3-4 minutes carving them out from huge blocks of ice whenever they have down time. Then when they're done, they toss 'em into a bucket in the freezer.
When I asked the bartender whether they make their own ice, she said they outsource it and just buy huge blocks from some company. Must be expensive, I'd imagine.