This cartoon by Paul Thomas from The Daily Express refers to the news that the Queen, returned to London from King’s Lynn on a scheduled train service at the end of her six-week break at Sandringham. Read more >>
We see the Queen sitting in a railway carriage. She is wearing a headscarf and the royal handbag is on the seat beside her. (ER stands for Elizabeth Regina, the Queen's monogram. 'Regina' means 'Queen' in Latin.) The man sitting opposite the Queen (who, we must assume, is just a regular passenger), says, "Give me another clue—your face definitely rings a bell ..." The Queen does not look amused.
If you say that something rings a bell, you mean that it reminds you of something, but you cannot remember exactly what it is.