Yes, that's what the "put through a virtual Kepler’s detection scheme" part refers to. So she:

1. Generated a bunch of random planet sizes.

2. Simulated what the detector would have reported for each.

3. Compared those virtual detections against the real detection data.

If the two results had matched, it would imply real solar systems have random planet sizes and the bias they see is from the detector. Since the two results are different, it implies the actual solar systems are not randomly sized with the apparent uniformity coming from detector bias.

(There could, of course, be a third factor where planets are randomly sized but the measured bias comes from something else.)