Self topping plant?? I have a question...

In my garden this year, I've used bag seed of some of the better stuff I've smoked so I didn't expect all plants to be the same. And they aren't.

There is one plant I have...it looks to be dominantly indica...but it self topped itself? At about the 4th node it didn't sprout vertically at all it sprouted the two new stems and it is staying low and bushy. The new leaves growing are almost cartioon like. It looks healthy. It's a darker green plant with defined, fatter leaves.

Any idea what this could be?