Basic "warmup" exercises at the start of every class. Everyone does them (or should be doing them). Some of the more obvious exercises like the wrist exercises are precursors to actual techniques themselves, e.g. ikkyo wrist pin, nikkyo, sankyo (2 versions), yonkyo and gokyo. Others like hip rotations, are preludes to koshi-nage techniques. And others like fune-kogi undo (boat rowing) are "ki" building exerises, focusing on joint alignments and moving from "center".

What other exercises do you do and what do they mean for/to you?

Or are they simply "warmup exercises", in preparation for actual training?