And you missed my point, maybe in a follow up: JV tried to take it to Tadej in all forms including descents, pushing on the flats prior to the last climb, etc. Tadej rode much more intelligently than their collective and ultimately wasted effort. His output on this stage had to be major percentage points below Jonas and the other JV crew before the last climb. And, to be honest; I only watched the last 60km.
I've ridden those roads in that heat and, very importantly; in those headwinds down the valley prior to the last climb. Tadej stayed under JV cover, retrieved a bottle for Sivakov who paced until he couldn't and then attacked to minimize the combatants. Smart choice made easier because Jonas and others threw in the towel.
You were very observant that he got out of the saddle to attack this time where on several notable recent stages he did not. On those other occasions his guys ramped the pace up so high it wasn't necessary and his pilot fish, Vindegaard was not prepared. Blowing up on a hill is easy after that much work. Today Sivakov wagged his elbow and then he blew up completely. Tadej jumped out of the saddle as they were nearly at a standstill and Jonas responded, albeit a little late.
Once Jonas checked his pulse/wattage he assumed the one intelligent response of the day: ride his pace to maintain the small gap. That was fine with Pogacar who recognizes there is one more stage and nothing more to do but stay out of trouble to win the overall and finalize this prep race. Yes, that's all it was to him and presumably everyone that rode treated it similarly. They'll all make improvements before July and we'll get to see the next edition.
As for Jonas' expression on the line; watch the 7 km before and he was totally under control riding in the big ring at almost identical tempo to TP, and at a well disciplined output. No heroically painful facial contortions; just the brutal efficiency he is capable of. His last km was all out and, at 6,000 feet you would look like that if you'd only ridden a few km warmup before that attacking effort.
What's discouraging in the disparity of our impressions is that we should see the same, entire video. I stand by the 60km I saw.
You're correct: the physiological gap is surely not as close as 15 seconds because Pogacar didn't require more time. At almost any time Jonas' composure was evident on his face. It's very easy to see because he was right behind Pogacar for nearly 100 km until Tadej dropped him. Then the dramatic look emerged in the last km. Fact.