At Sight

Question: What is "at sight"? Answer: When you should pour cold water on a mime.
Actually, it's a term relating to the timing of payments under certain contracts. Most of the time, a company will give a buyer some time to pay their bill, say 30 days. "At sight" is the opposite of this. Basically, a buyer is expected to pay immediately, at sight of their bill, as it were.
An "at sight" clause might get added if the seller thinks the buyer presents some payment risk. If for instance, the seller had trouble collecting from this buyer in the past. Instead of chasing them around for payment again, they might insist on an "at sight" clause in order to get paid immediately, lowering the risk that the seller will get stiffed.
BTW, according to our lawyers, mime is a perfectly respectable art form and we wish nothing but security and health to all its practitioners. In fact, we're pretending to be stuck in a box right now!