The structures are built to model those of the actual city of Venice. The ceiling is even made to look like the actual sky. The environment is so interactive you will feel like you are actually enjoying a nice sunny day stroll in Venice. You will feel like you are actually there except for a few minor details like the Chinese Signage that might give it away.
source: http://www.goodfoodandtravel.com/venetian-hotel-and-casino-macau