52-54 White Post Lane
London E9 5EN
This picture comes from the always entertaining World of Good Flickr stream, managed by Tim Rich and Lesley Katon. Mr Rich also writes a thoughtful blog at 66000milesperhour alongside colleague Tom Lynham.
The sign is reportedly on Trago Road in Hackney Wick. Online research suggests this must historically be connected to the nearby Mr Bagels production facility on White Post Lane.
This appears to be an older version of an identity that has since evolved to include an apostrophe, indicating that this is a business belonging to Mr Bagel, rather than Mr Bagels. However, the website continues to use Mr Bagels without the possessive apostrophe, so we must take it this is the predominant rendering.
The Mr Bagel(')s website also includes some useful information on the origins of the bagel:
The origin of the bagel began in Krakow, Poland under the influence of the Polish King Jan 111 Sobieski.
Upon his return from the war a baker made a stirrup shaped bread in honour of the King which became known as the Bagel or Beigel which originates from the German word for stirrup.
An article on Wikipedia disputes this etymology, but I'm afraid I couldn't help losing interest halfway through.