Provided the meter is working exactly, minor variations within the profile validation suggest that the monitor's characteristic was detected correctly and remains stable. Now the CMM (Colour Management Module) of colour-management capable software is able to transform to monitor-sRGB as perfect as possible, which is limited by the monitor's colour space at the latest. If the variations increase noticeably later, time for another calibration and subsequent profiling has come. Users will profit from all changes to screen settings and video card LUT, which are expected to lead to a neutral grey axis, desired gradation and white point, performed during the calibration. This even implies non-managed settings.
If the variations shown in the profile validation are too high, the displays shows strong drifts after a short time, or the actual measure values that are related to D50 could not be written into the profile. That is the case if significant nonlinearities occur, which is why the display does not suit for electronic image processing.