+ AA6YQ comments below
I use DXKeeper for my main log.That pop-up tells you the particular card qualifies for an award (or advances your progress toward an award). The example you cite indicates this is your first LZ6 prefix on 80M and CW.
+ The award is one that you've configured DXKeeper to pursue (via its Configuration window's Awards tab). If you don't want these "submission reminders" to appear when you mark a QSO as confirmed via QSL card, uncheck the "Submission reminder" box in the "Log Settings" panel on the Configuration window's Log tab.