Which Target Estimate is selected by VPhot when multiple are used?

British Astronomical Association, Variable Star Section (BAA-VSS)
Thu, 11/02/2023 - 19:46

In the Single Image Photometry Report page at the bottom we see the comparison stars tabulated and the column

"Target Estimate" where one of the targets is selected to assess the reliability of all the comp stars.

How is it selected? Can it be changed?

I played around deleting some to see if it's maybe the brightest but it's not.