Hi,
If SQL starts up and take all the memory and do nothing with some of it...is that not waste ?
The recommendation is based on the Active memory usage of the VM over a period of time. This is default over a period of one month.
There is under/over size settings that you can set and they should be set to your enviroment.Oversize Thresholds could be set to 70% and CPU/Mem demand to 30%.
What you are seeing is that Windows is showing that the in Guest memory usage is 7.67Gb. Looking at the vSphere Screen you can clearly see that the Active memory is only 2.24Gb.