looks like someone took the lid and cut it so it's the same size as the left compartment.
Based on what I've seen online, I bet it looks identical underneath to my White rotary with the door.
Imagine a panel attached to hide the electrical and belly pan - it will pull up out of the way along with this part.
This shows starting to open the lid - your lid has been modified.
Once fully up - the knee bar hooks on the lever on the speed control and extends out from the side of the cabinet.
BTW - with yours you would not see this, as the skirt would be folded back and hiding it all.
And another, because this machine tilts BACK - you must have that screw in the front holding the machine in. Singers tilt forward so don't need something like this.