Maybe more than anyone ever wanted to know about this stuff, but you asked something that I could answer and think about a lot. You can see that it is a little shiny and looks a bit stiff, versus Dungey's which you can see the material weave inside the lettering and name like the rest of the graphics. The Tedesco jersey is a little older, back when even the pros got jerseys with plastic ID's, but oddly enough Roczens is vinyl as well. I can't explain why I haven't seen anyone who offers ID kits use anything other than that thick, shiny, stiff vinyl, though there are actually some much better heat transfer films out there that are pretty thin and stretch fairly well (possibly because of the moderately higher cost).
For the rest of us non-factory riders, jerseys come to us already saturated with ink and unfortunately adding more ink in the same process wouldn't show up, so we have to layer over it with a physical material to block out the base colors. I would assume that he gets it because Fox actually adds his name and numbers into the graphics as they print the full jersey. The jersey ID's that Dungey and a lot of the other pros have are sublimated (ink printed into the jersey fibers), which is the way textile graphics are mostly printed these days.
