Establishes George Jefferson (unseen at this point) as the owner of Jefferson Dry Cleaners, a dry-cleaning store franchise.
According to Archie, George had formerly been the "head janitor" at the nearby Hampstead Apartments, which is apparently how Lionel had got to know the Bunkers, leading to him doing odd jobs for Archie.
Mike has a brother-in-law for this episode which means he would have a sibling who is never mentioned. The only relative of his ever to appear on the show is his Uncle Casimir.
George was said to have just expanded his Dry Cleaning business, opening up a store on Northern Boulevard. Lionel explains about the franchise his father had set up (apparently their first store being In Harlem), funded by a law suit settlement when George and Louise were rear-ended by a bus. On The Jeffersons, it would be established that George opened his first Dry Cleaning store in Harlem in 1968 via a bank loan.
This is the first of a long line of times in the series where Archie attempts to lie in the name of greed only to by found out in the end. Here he fabricates the accident he was in.