A case with actual drive bays and ribbon cables everywhere, it if wasn't for that AMD Wraith cooler I'd think I was looking at a machine from 20 years ago.
Doesn't look like there is any other side at all which is fairly common in older cases (and possibly new pre built).
The metal plate you see is probably the side panel.
I guess they could probably fit some small cables between the motherboard standoffs but that's about it.
Guessing that this is a somewhat older case, the power supply being at the top like that it's pretty close to the motherboard and CPU power sockets and the drive bays, and GPUs could often run from motherboard power. You might have those huge grey IDE ribbon cables for floppy drives, you usually had the ketchup and mustard power wires, who cares what the thing looked like inside?