There are 3 screw jacks visible in the photo. The one almost against the chimney is under a major beam, and one can hope that the chimney area has a thicker concrete footing under the floor pad and that jack. But the two screw jacks in the foreground are unlikely to be over a thickened footing, so they are more or less now point loads on the floor pad. Not really the best way to do that. Ideally, they should have cut out a section of the floor pad, excavate and create a new footing. Or a redneck alternative
would be to put a big beam on the floor that spans somewhat beyond the feet of the two jacks, and place the jacks on the beam to distribute the load.
