I did a search and found only two statutes with the word 'brandish'. One was about not brandishing a firearm while in your vehicle on school property and another was about doing something similar while on an employer's property if they do not allow employees to carry firearms at work. I didn't find an actual offense such as brandishing a weapon. It's either named something else or doesn't exist in the KRS.
I would be mindful of your surroundings. If you're at the mall or in a store and you take your shirt off to reveal a firearm that might make people more nervous than if you just walked in OCing. It's kind of like the guy who had his firearm sticking out of his pocket. While not illegal since he had a CDWL it is still suspicious. I would probably go to a more private area if I was going to go from CC to OC, say a bathroom or to my car.