Good fortune comes from a smiling gate?

笑門来福：わらうかどくるふく：warau kado kuru fuku

Literally, smiling/laughing gate comes fortune.

NTT, on their calendar, translated it as "Fortune enters through a merry gate."

How about "Fortune comes in through a laughing doorway?" Or maybe a smile brings good luck? When you're happy, the whole world smiles with you?

Any way you look at it, there's some kind of connection there between smiling and good fortune.