Flange yoke seems inverted

I'm building the lightbox, and I am having trouble understanding the flange yoke for the pneumatic squeezer.

In the attachments, picture #1 has the shop side of the flat set on the ram, which is great because it causes the shop end to meet up with the rivet, allowing me to keep the flat set in contact with the factory side. But in this setup the hook of the flange yoke is useless. It doesn't hook over the flange.

In picture #2 I swapped the heads so the hook part of the yoke hooks over the flange on the shop end. But in this setup it is much more difficult to set these rivets. The flat set is on the moving ram, and it is difficult to keep the flat set in steady contact with the factory end while the ram is moving.

It seems inverted, as if the "hook" part of the yoke should be on the bottom so it can hook over the flange on the shop side. What am I missing?

Use the tool as necessary to accomplish whatever the task presents. There is no right or wrong in this case, just whatever makes it easiest.

+1. What you (OP) said is correct: it’s easier with the ram moving to the shop side. But sometimes you just have to invert that. Try this: with the ram on the factory head, apply a modest amount of pressure on the squeezer, against the factory head, and carefully apply just enough pressure to the squeezer trigger to move the ram. When the fixed side of the yoke flat hits the shop side, the ram will stop. Check alignment of both sides of the squeezer on the rivet, keep pressure on the factory head, and open the squeezer trigger all the way if everything is straight. If not straight, release the trigger and start over. This technique can also help when riveting with the ram on the shop head, just to be sure of the alignment.

+1 on What Scott said

Picture #2 shows normal orientation for that yoke. Even thought it would be nice if you could always put the stationary side on the manufactured head, it not something you can always do.

Having a squeezer with a good trigger really helps. Even though I much prefer to use a pneumatic squeezer, there are times when a good hand squeezer gives better control.

Longeron yoke

That's funny. It's a longeron yoke. The depth is to clear the longeron flange so technically it's backwards. No worries. As mentioned, whatever works. Usually the smallest yoke yields the best results.
I actually prefer the ram impact the factory side. It insures the factory side gets seated. However, it's improper technique and a dangerous way to set rivets but, that's how I'm comfortable using it. What the heck do I know.
Probably why I always choose gun and bar first.

Thanks for the replies. I did eventually get all the rivets set with the sets swapped (flat set on the ram). Because it is more difficult to control I ended up having to drill out 8 of 40 rivets. And I may have bent one of the nut plate holes. On the plus side, my rivet drilling technique is steadily improving.