During the validation, the upper part of the dialog shows a table with the backups selected in the previous step.

Below this along a timeline the databases are shown in the backups as bars. If you position the mouse in the timeline area, you can zoom with the mouse wheel. You can move the time axis with the mouse on the time scale (keep the left mouse button depressed).

In the lower area, there are two signal tree windows A and B. Use the option fields in the columns A and B of the table above to decide which signal tree is shown in it. In this way, you can compare the signal trees and, for example, check whether the backups match each other.