Moss looks like he is squatting, thinking it is C2 (or quarter-quarter-half). But the rest of the secondary looks like C3 (Schulte and DeJean are dropping to deep 1/3s).
They were bringing simulated pressure, blitzing Benson but dropping Evans (Evans was supposed to be underneath the crossing route, but he looked a little clunky in space, as you would expect of a DE dropping into coverage).
Iowa has been blitzing a lot more than usual (and pretty effectively) since the 2nd half of the Michigan game. As fans, we often think blitzing is just a 100%, sure thing, solution to all that woes a defense. But it does carry risk as well, which we can see here. Even though they only brought 4 and dropped a DE, in retrospect probably would have been better off playing it straight up here. Oh well, can't win them all, and I trust Parker's decisions to roll the dice above any other D coordinator in the country.