Guessing they had a guy playing centerfield.
That's not in the box. Has to be closer to the LOS to be considered playing in the box. The guy playing centerfield is playing pass. The 8 in the box are strictly playing run.
They're definitely playing the run. But they're also guarding against the pass. 1 has the outside tight end (they're double tight on the right side) if he comes out, they guy on top (25?) has whoever is split out (Moore?). Backers are filling gaps, not dropping back at all.
I would have motioned Kmet, 1 probably would have followed him, then countered to the side Kmet vacated. Instead of running up the middle into the backers. But hey, that's just me.