I used to own one of those HED front tri spoke wheels, the 3c full carbon tub version. I'm pretty sure in that photo, the trispoke is on the bike backwards. The three spoke legs are directional because they have an airfoil shape. Even the modern open mold Chinese ones are directional. But now you have to pay more attention as many moved the valve stem hole to the rim and not inside the spoke leg. The giveaway of how to mount them was the indention in the trispoke leg. I'm guessing to reduce weight due to a complicated carbon layup that adds weight to have a hole in the leg of the wheel. I'm pretty sure the hole in one of the legs where you get to the valve stem should be facing so you can see it in the photo if the legs are facing the right way so as the wheel spins it's spinning the correct way. Probably they did this for a nicer photo.

Scroll to 5:39 in the video...........listen for that HED trispoke.....
Here was my HED 3 mounted with the spokes spinning in the correct direction, note you can see the hole in the spoke for the valve stem facing you in the photo.



Also another "Lance era" TT bike with that same wheel showing it mounted correctly:


And below is the "modern" trispoke that Bigham and others are running in TT's, that despite having a true "vendor" is actually an open mold Chinese wheel...........this one is mine..... "Modern" because over time deep section wheels moved away from the sharp trailing edge to improve aero at a yaw angle other than "zero" or head on. They did this by rounding off the trailing edge. The "modern" ones have the same deep section profile of modern HED and ENVE style aero wheels by redoing the shape where the trispokes meet the rim. The trispokes themselves are also a more rounded/blunted trailing edge to improve aero at non-zero yaw angles. They also fit wider tires now. I run a 23mm on a 27mm wide rim version and inflated it's the profile you want. A 25 would work great also at a super minor aero penalty if you needed it for a bumpier course. Note as these are unbranded but the pros run them anyway in TT's, the MUST be good enough to justify that. It was a bad day for testing, but I had that wheel at about .007 faster than a HED 9+. Which is not trivial at all.