This has been particularly interesting to me because I can usually only relate to system design in software visually. It works wonders for me personally to see

This has been particularly interesting to me because I can usually only relate to system design in software visually. It works wonders for me personally to see code blocks as literal blocks that do X and connect to other blocks via graph edges. Then I pseudocode what I want and replace. Whiteboarding is a bit difficult if I can't visualize transformations or stores of data in some way, or if I can't see a theoretical big picture for a particular function.