Or is it not? what else can it be?: Was that exciting, or what?/ Is this the old trickle-down theory or what?(1990s+)
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with or what
A phrase following a statement that adds emphasis or suggests an option. For example, in Is this a good movie or what? the phrase asks for confirmation or agreement. However, it also may ask for an alternative, as in Is this book a biography or what? In the 1700s it generally asked for a choice among a series of options, and it still has this function, as in In what does John excel? in imagination? in reasoning powers? in mathematics? or what?