Why do circuit boards use strange paths?
These "complex paths" are simply a way to make the paths longer. This allows you to match the length of two or more tracks on the PCB. This is important for high-speed (MHz) signals, where the time taken for the signal to travel along the tracks on the PCB (an electrical signal travels at around two-thirds of the speed of light in copper) is comparible to the signaling rate. If the lengths were not matched, then the bits on one line in a parallel bus (such as the GMII link between and Ethernet PHY and MAC) would arrive before the others. This could mean that the value on the bus is read between the first and last bit arriving, giving an incorrect or invalid value.

In the example you provided, you'll see that the top-right pair of tracks has the least distance to go in a straight line between the IC and CAMERA connector, so it has the most extra length added to the tracks.