Lawman, Anchovy is just a seasoning, like salt and pepper, a flavor enhancer. It doesn't change the actual flavor of the burger the way something like Worcestershire sauce or onions do, it just adds a bit of umami that makes ground beef, um, beefier. I use anchovy or fish sauce in many of my dishes and people don't know what that extra flavor is but they know it tastes good. As the saying goes, don't knock until you've tried it. Your pizza looks very good.
Don