While riding a train in New York City in 1896, Henry Heinz saw a sign advertising 21 styles of shoes, which he thought was clever. Although Heinz was manufacturing more than 60 products at the time, Henry thought 57 was a lucky number. So, he began using the slogan '57 Varieties' in all his advertising. Today the company has more than 5,700 products around the globe, but still uses the magic number of '57.
This is from Wikipedia.
A "Heinz 57" dog is a mixed breed dog of uncertain ancestry- a mutt. The name refers to the "57 varieties" Heinz slogan.
Its about the pickles
57 heinz varieties
57 Heinz Varieties
57 heinz varieties
57 Varieties of Heinz Ketchup
57 Heinz Varieties
57
57 Heinz Varieties
Heinz 57
57 Heinz Varities This can be seen on the label of all Heinz products and represents the number of products Heinz has. These problems are called Ditloids and there are many many more.
It can stand for a lot of things, i.e. 57 Hydro Vac, 57 Heinz Varities...