It's genuinely jarring because some places don't organize it logically so you're scouring the board and it switched and you gotta figure where you were ... makes me wanna slap the person that came up with this idea.
It's gotta be intentional. You and me might walk into a restaurant and make our own decision on what to order, but there must be some sort of market research that shows random ads and rotating items to be effective against a non-zero part of the population.