to the left, to the left

I was looking into some cases when I noticed something in my peripheral view, when I turned to get a look, I noticed that the air force is doing some exercise. It was quite interesting so I watched for a bit, not more that a few minutes later, two of the planes went to the opposite direction and took a vertical path, then at a certain point, shifting into again, opposite directions slowly moving down, their paths crossing again some 50 meters later to form a giant heart shape.

I'm not into cheesy things but, I must admit, it was kinda cool.