Not a very descriptive name! The blank is made up of contrasting wedges
Two square bowl blanks, walnut and ash are sliced into four wedges
The ash wedges are rotated by a right angle
Then the middle two wedges (walnut and ash) are interchanged
The four wedges are glued and clamped to make a new "bowl blank"
The top and bottom faces are still parallel. Edges trimmed to octagon on the bandsaw