Strange shapes on the Wi-Fi module PCB
Probably slot antennas, you could figure out the length by the width, length and the material around it. I'm not sure if these are antennas for the wifi module or a way to null the RF from the wifi modules (I'm not an antenna expert, I mostly design things to stop RF propagation). They most likely had a electromagnetic FEM solver to design a board like this to get the right antenna pattern.


Source: https://www.sciencedirect.com/topics/engineering/slot-antenna