Bangkok is one of the shopping meccas of Asia, and every few months there is some new opening somewhere. One of the relatively new additions is Terminal 21 - an travel themed shopping mall with a different destination theme on each floor. It is supposed to feel like an airport terminal and was opened in 2011.
The various destinations themes used are London, Tokyo, Paris, Rome, San Fransisco, Istanbul, etc. Some themes are more obvious then others.
On the whole it is not that different from other shopping malls. The same International and regional brands are represented - plus some less local brands. But if you are looking to do some shopping it is not a bad place, and there is a nice food court at the top floor - Pier 21, which is clean and cheerful.