Rotated ICs on PCB board
One significant reason for placing larger components on angles is how that affects the routability of the board.

Consider the following two crude layouts.. (Please ignore the difference in track spacing.. it's more about the vias.)



Because SMT parts won't normally allow you to pass a trace between pads, the requirement to use vias and tunnel under has become much more prevalent.   However that requirement has always caused an area where you can no longer add vias as shown in the triangular area under the left chip.

Vias themselves are usually placed on a 45 degree angle relative to the track axis so as to maintain the track spacing while allowing the via pad to be larger than the track width.

By rotating the chip to also be at 45 degrees you can get rid of that triangular no-via zone leaving a lot more room to bring in and connect the remaining traces to the device.

Whether the board shown in the OP's question was done for this reason, or to balance line lengths etc, who knows. However I suspect it was mostly done just because they could and thought it was cool.