It appears to me that he is using a olive wood trunk “disk” to make the rib/top block/tail block piece.  If so, he is glueing the top and bottom plates to “end grain” on the ribs.  This will cause a poor glue joint, given the microscopic “drinking straw” matrix of the end grain.  There are ways around this issue once apparent to the builder.

Similar could be done, and likely more effectively, using a band saw.  No rib bending obviously would be required.  And it may be possible to nest patterns one inside the other in a Russian Doll manner, to maximize use of the disk if one was building an array of different sized instruments.