EDIT: Well apparently I can't hotlink from the original picture, and can no longer get to the original, but the sign said "Look Busy, Jesus is Coming" If I find it again I will repost.
This sign is a blatant showing of legalism. The sign would cause us to believe as long as we look busy, God will be fooled. One can only assume looking "busy" refers to works, for why would Jesus want us to be busy. This is a classic guilt trip church sign; you know the kind that make you think you're doing something wrong and if you would just change that behavior and go to church then God would be happy. The other reason is it appears to insinuate that God can be fooled. We know that God is omniscient and omnipresent, so there is never any reason to "look" something rather than just being something, for God knows your heart and motives.