Freeze it at Ball Out and compare to Box. Same flood, but now there is a hat at every level. The cloud corner sat the flat, the half safety capped the go, and the nickel sank into the curl and is sitting right on the sail. That out-breaker that ran into open grass against Box has a defender on it here. That is the entire reason this call exists.

Watch the inner seam. The cloud corner carries the outside go up to the half safety, and the half safety takes the next seam. But the third receiver runs straight up the middle of that half and the nickel cannot run with a vertical from the curl. The inner seam splits the field, because clouding a three-receiver side leaves you one deep safety short. Box's job was rubs, this call's cost is verticals to the clouded side.

This is the snap that burns people. Look at the boundary: your cloud corner and a half safety are both sitting on one receiver running a curl, doing nothing. Meanwhile the flood hit the quarters side, where the corner is deep on the go and nobody owns the intermediate out. The sail is open in the exact void Box left. Cover 6 only helps the side you cloud, so read the flood and check your cloud to it, or a motion will move the bunch off it.