I agree with whoever said, sloppy job. And if one skimmer isn't level with the other then u may have water problems as one skimmer having more suction then the other. and the table where the skimmer face faces, where the tiles are looks crooked also. Im sorry to say but that is poor quality of work. and the proper way to set a skimmer is just as fignewton said, and take into consideration when mixing the cement, to use a large amount of Calcium clouride so that when u are attempting to set the skimmmer, the cement sets up quick and is stiff so that u aren't playing around with the skimmer and is set properly withing 10minutes.