When Charlie first walks into the bar, Dennis is painting the third line of the sign. As the camera shifts frame from Charlie, to Dennis, to Charlie, then back again, fewer words on the sign are shown.
As Charlie takes the truck driver to the 'patio' they pass a green topped stool with silver duct tape on it; when Charlie returns, incidentally slamming the same stool down, the tape is missing.
When Charlie is walking the Health Inspector out to her car on the sidewalk outside the pub, there's a sign in the background advertising a business with an area code of 213, which is in Los Angeles where the show is filmed.