Since I am an American, I can make the following observation without the risk of insulting my fellow countryman: the restaurant had American tourists in mind when they created this appeal. How do I know? The sign is in English in a Spanish speaking country, of course.
A friend of mine who who stayed in our condo last year got such a kick out of this sign that he mentioned it in an email. I guess the sign accomplished its purpose, as it attracts attention and causes the restaurant to be noticed and remembered, as least for the size of its nachos.