Shop owners are allowed complete freedom to use any materials in the game. There are a couple of shops that have LEDs - most of them do not. There was one space that was used to make a youtube video for the game, but it was enclosed as to not annoy shop owners. There are no blinking LEDs used in the structure of the mall.
I do understand your concerns. I have family members that have epileptic and grand mal seizures. I do not believe the game has any lights or blocks that could induce a seizure.
I am almost certain that the computer screen and phone screens are brighter than the LED or gleam blocks in the game. The display can be toned down by: settings > display> brightness (and turn it down).
I believe you can see the LEDs in certain shops from a distance without getting too close and avoid those shops, if needed. If there were items in particular that you were searching for, I’d be happy to assist you in locating them.