It's an optical illusion, due to the curvature of the earth and lack of reference points over the ocean. The contrails are actually horizontal, and the airplane is flying roughly toward you.

You're probably familiar with a similar optical illusion. Have you ever seen a full moon close to the horizon at moonrise, while the sun is setting? Did you notice how huge the moon looked? Well, it's actually the same size as it is a few hours later when it's overhead. Again, due to the curvature of the earth and the profusion of reference points near the horizon, it looks larger.

Onward and upward,
airforce