MacBook Pro 13 headless lower plate peeling off

It looks like the bottom cover casing isn't even screwed down? You have to put it all back together as though it still had he full display assembly (Minus the display assembly) but obviously keeping the antenna and clutch cover to have WiFi access.

This video from a 2019 15" should be a similar pocess.

MacBook Pro (13 Zoll, 2019, 2 Thunderbolt Ports) Displayeinheit austauschen

Sometimes we exceed what is practical, Apple engineers designed the system with the idea of the display frame as part of its rigidity structure so when you took it away the back side of the uppercase can't leverage it to support its self!

I've seen this a few times where people took the display off trying to overcome the failed display so the system could still be used. Over time the uppercase fatigues cracking and/or causing the logic board to flex which in turn creates a failure within it.

But the worst of it is while the system will run it wouldn't do what it can performance wise! You see Apples SMC logic senses the loss of the display and goes into CPU Safe Mode as the Intel chips tend to overheat! So the CPU clocking is reduced and the cooling fan is pushed to the higher RPM's

So while you gained access to the keyboard and trackpad you will wear-out your system a lot quicker than just using it in Clamshell Mode with the display folded down and using a BT/USB keyboard and mouse! And lastly when needed get the systems full performance!