What you are seeing is a result of the fisheye effect of the lid camera. It’s going to appear to be closer right under the lid camera, and more pronounced out at the edges of the bed.
There is a program to correct for it called the Recalibration tool. Use of that along with Set Focus corrects the appearance so the results will come out closer to where you expect them to.
The Recalibration program is described here. Be sure to follow the directions closely.