Once the water freezes, the mold is stripped away. Increasingly though, chefs are taught ice carving as part of their preparation for the profession. You don't need to be especially artistic. The masters are choosy about their medium. They want blocks of clear ice only, with a see-through quality achieved in the ice house by keeping the water circulating as it freezes.
Big ice is over with.
Now we take from nature, beginning with drawings of a real swan rather than with something from an ice-carving book, and the impact comes from the lifelike detail. Both Dennis Wold of Ice Molds and Bill Twilbeck of Ice Magic are mold-makers. They both acknowledge the image-problems and both claim those problems are in the past. But how we do it is one of the secrets I don't care to give out. And they're going to look good.