If you’re an Americanist archaeologist: Nothing.
He is clearly within an undifferentiated layer of yellowish sediment. He’s been digging in arbitrary levels and pedestalled a biface for recording its depth, then will collect the biface and level the pedestal to the arbitrary “floor” he has excavated to in the rest of the unit.
If you’re a British archaeologist: Everything.
He has clearly hit a surface that the biface used to sit on, and he should have levelled to that floor to preserve context, recorded everything on the surface, then removed the biface and continued until he found the next surface, as signalled by a stratigraphic change or more artifacts. By pedestalling the artifact he removes its context.
Nice biface, regardless!
(My thanks to Travis S. for posting such a graphic example of this.)