The table was clipped from a long article which carried full details of all the joints. They were all at 90 deg making an L shape which was racked under a press.
The main mode of failure was through a split in the piece carrying the mortice, which commenced at the outside of the joint, and tended to come at the end of the "tenon"/biscuit. The authors were surprised at the winners, especially the splined mitre, which was in no way unusually constructed. The thin tenon, and the bridle joint failed when the "tenon" snapped under tension at the shoulder, the glue mainly still holding. The Domino lost out as the domino tenon used was a bit short for the 50mm wide timber whilst the loose tenon was in a max depth pair of mortices.
They also pointed out that the results may well be different after a few years of (moisture) movement, or indeed exposure to the elements