Stumped By A Preschool Game

Junior loves to play the Sandwich Stacker Cookout Game by Bloom (makers of all those fantastic Cranium products). It's a cute early learning game in which you stack giant pieces of plastic cheeseburger ingredients, trying to keep the yummy tower from toppling over. It's a great game for him, because it requires correctly identifying colors & shapes as well as using fine motor skills. (Plus, it highlights one of our favorite pastimes around here -- grilling!)

To play, you simply press the spinner to see what type of item you should stack next on the bottom bun. If the spinner shows a square, circle, or triangle, you choose a topping with that shape; if the spinner shows red, brown, green, yellow, or white, you choose a topping with that color. Most of the toppings are fairly obvious.

For example, this is a tomato slice, and can obviously be used for either RED or CIRCLE.

This is a slice of cheese, obvious for the WHITE category. It is also part of the TRIANGLE category, despite the curvy bottom edge.

Ok, now here's where the edges start to blur (literally). The ketchup is obviously RED, but also a nontraditional SQUARE. The edges are scalloped, the corners are uneven, it contains no straight lines -- but it still has the essence of square.

Now this is where I'm stumped. This pickle layer is a clear choice for the GREEN category...but I keep wondering -- is this supposed to count as a SQUARE or a CIRCLE!? My daughter sees a square here, but I tend to view 4 circles.

What is it?