It's illegal in most places to draw a gun and display it like that in public, because it is inherently threatening.

"Brandishing” or “improper exhibition” or “defensive display” or “unlawful display” (or whatever your state and jurisdiction calls it) depends specifically on your state and jurisdiction. Very generally, however, for an operating definition “brandishing” means to display, show, wave, or exhibit the firearm in a manner which another person might find threatening. You can see how widely and differently this can be subjectively interpreted by different “reasonable” individuals and entities. The crime can actually be committed in some states by not even pointing a firearm at someone. In some states it’s a Misdemeanor crime and in others a Felony. So, focus, think rationally, know your state’s law, and be careful out there.