Yah - Those pipes look like they have expansion chambers... V. Strange for a 4-stroke.
An added tidbit on the motor - Yes, it's a V-4, but the pistons fire in pairs so it will sound and behave like a twin... They did that because they couldn't get enough valve area to make the power they need, but still wanted a "twin." Ducati apparently looked at a pair of oval pistons with 8 valves per, but decided the weight break for twins wasn't enough to make that choice advantageous. Hence the milti.
i think it just "looks" like an expansion chamber due to all the "twists" and "turns" necessary. and fabricating out of titanium (tig welding) gives it that look too when your hand fabricating and don't have the resources (or the time) to produce the titanium formed and bent to shape. for example, here's a close-up pic a posted a while back of the blackmans/tigcraft Ti exhaust for the mille... and then again, being that it's expected to rev so high (ie. akin to a 2-"smoke") ducati may very well have added a bit of "tuned pipe" elements to help with scavenging...? i wouldn't put it past them or any of the others... if it helps power at peak rpms... do it...!!!