The table underneath the sewing machine is an older sewing machine flipped under. You flip the sewing machine into the top and it becomes a table. The new machine is on top of the older machine.
Here is a picture of the same type with the older machine still out of it's nook:
I’m familiar with that type, but I think the old machine was removed. It would be visible under the table. Hard to tell for sure with the poor lighting though.
You can't really see the machine when it's tucked in. Here is an example:
Edit: This normally would have an extra bit in front of the sewing machine to cover that part up (see above for an example). This was just to show that the sewing machine is under the table but still not very visible.
It wouldn’t. I still have one here at home from my great grandmother. The machine disappears completely inside the table top with no parts visible. Like in this pic. Pretty sure it’s the same model as I have here.