2015 Macbook Pro screen glitching

I always borrow my mother's 2015 13" Macbook Pro for school activities. Yesterday , after pulling it out from my bag, I was surprised due to its screen glitching out.

The laptop is in a perfect condition, everything still works. It is not damaged, no cracks or whatsoever. It hasn't made contact with liquids.

I am just really shocked when I lifted the screen up and the screen appears flickering and glitching. I tried resetting the NVRAM and the SMC by following the instructions from the internet. I also tried changing the resolution of the screen but nothing happened. I did try booting it into safe mode , still the same. I even updated its software to the latest MacOs update, 14.14.6

The glitching starts at the beginning after booting up the mac or waking it up from its sleep. Eventually the glitching stops or sometimes subsides, but the flickering is still present, plus there are also tiny, grey, semi-transparent lines all over the screen.

The way it glitches is like having hiccups, it goes bright for a second and quickly dims, and then it refreshes what is displayed on the screen, and then repeat. The flickering is self-explanatory.

I have no idea what caused this... I don't even know if this is a software or a hardware problem. What should I do? I have some pictures and a video, just in case someone needs evidence.