The sign over the door seems to say "25 chips (for) 25c", or a stack of 25 chips for a quarter = 1 penny per chip on roulette. That matches the "Penny Roulette" sign offer.

So the MEC chip may be one color of the penny roulettes being offered at the "Annex" next door that did the penny roulette game.

But that also begs the question -- where are the other colors of roulette chips??