Pictures might not be of much value since it'd be hard to see where the mulffer is/should be placed.

It might be more useful to measure where the new muffler is attached... compared to the stock. Better yet... measure from some stock fixture along the stock exhaust (ahead of the muffler) to the PV. That way we'd all have the same reference point.

Recalling some high school and college physics courses, I think WyrreJ's theory is correct.

I find it hard to believe that they did not weld on an extender pipe. Isn't the PV shorter than the stock muffler? If that is indeed the case, they would have to weld on a pipe somewhere (ahead or aft) to make up for the difference in length.

If you're going to spend the money to have an additional muffler put in... then you might as well have started with a complete custom exahust system. I'd do what WyreeJ suggested before spending that much time and money.