Well, that's just silly. Clearly, she is obstructing the view of the driver to the rear of the cab. Furthermore, she will likely distract other drivers, not to mention that she is in a completely compromised position in case of emergency or an accident.
I'm really surprised Cbid posted this pic. Very irresponsible. Plus, it will encourage me to try steering my truck on the way home without using my hands, and that can't be a good idea either.