While the glass may not be cracked it appears the LCD Panel is cracked.
I see you have a camera cover installed and the crack is right next to this camera cover. Probably just grabbing the closed laptop would have exerted enough pressure against the camera cover to cause the LCD Panel to crack. Or maybe it occurred while in a laptop bag when something pressed against the laptop (again pressure against the camera cover). These Apple laptops have very limited clearance when the Display is closed so you should not be using any camera covers or keyboard covers as it can damage the Display. If you want to cover the camera, then use a piece of a Post-It Note.