Have tried everything on google, but there's nothing. Why is there a CD / tray?
Can't imagine a picture… A compartment, but not a drive? What do you mean by subject? Ne flap that does not open?
I used to have a SIM card on my company notebook. It said "Simcard Slot".
My new EliteBook has it too. Did not get the part but. I talked to our IT for half a day, until one of them found out that it was just a dummy flap in the case of the notebook, and the model behind the fittingly labeled "Simcard" slot is nothing, nothing at all.
Maybe you're just dummy with you?
So stupidity should really be banned.
If you want to install a drive later, the compartment is already there.
Otherwise, the same housing will be used for different laptop models. If one of these models has a drive, all models will have the compartment in the case.
Probably I have the same housing devices with optical drives. Also, this could be retrofitted, or by adapter, a second hard drive.
If the manufacturer can use the identical housing for different models, this is of course cheaper than making a separate housing for each model.