I know very little about Cao Đài. It's a relatively recent religion, founded in the 1920s and based in South Vietnam. It's a fusion of several religions and incorporates some very odd elements from other sources - my personal favourite is that Victor Hugo is one of their saints. For more information, see Wikipedia's entry on the religion.
Here's a closer shot of the sphere behind the altar:
Yes, that eye looks very familiar to people in possession of an American dollar bill.
I hope to get to Cao Đài headquarters in Tây Ninh and visit the main temple there.