No, it is not a building out of Star Wars Episode IV! Qasr Amra is by far one of the most well-known of Jordan's desert palaces. This particular "palace" was once part of a larger complex and it remains a frequented tourist destination today.
Qasr Amra is most well-known for its frescoes - which bridge the gap between Late Antique and Early Islamic iconography. In other words, it lies at both an art historical and geographical crossroads. Tourists are difficult to avoid, but try to take a quiet moment to take in the sumptuous figures and keep an eye out for some Ancient Greek on the walls!
PS - On your way out to Al Azraq be sure to ask your driver to stop and get a picture by the road signs pointing to Saudi Arabia and Iraq.