Sowerby certainly did shape "standard" items differently on some pieces. One that benefited from a range of fabulous shapings is the Diving Dolphins bowl (at least six different edge shapings). Even little differences such as the cupping in or flaring out of a vase mouth, can be found, for example on the "Derby" vase. And of course, the Iris and Lily vases are a good example of variation, along with the Frog & Bullrushes vase that Leni mentioned.
From time to time a "whimsey" turns up too (a quirky shape that wasn't "in the line"). I have a very weird and wonderful "Pineapple" shape (Sowerby's 2349). :?
However, I hadn't seen one of those 2634 salads (aka jardiniere shape) flared out like that before. It's a beauty. Incidentally, in Carnival Glass (yes it's known in Carnival) we call that pattern "Jagged Edge".