If you are not driving the car for months at a time, you should be disconnecting the battery cables and using a trickle charger. Especially during winter months if you live a cold climate.
Yes it will flash all the time and it doesn't take much power so no need to worry. My car will sit for weeks at a time and it hardly drains the battery.
If it's not flashing in the showroom then, chances are the negative cable has been removed for safety and insurance purposes. Perhaps there's another reason since mine is pure speculation.