How do you assess, that this is not “resolution stated by them”?

If you zoom in to the area, so that you will see individual pixels, then use a measure, you will see that pixel is 0.5m long, exactly as stated (you will have to measure two pixels, as the measure only shows meters…).

In case you are referring to the “10m scale” on the bottom right part, note that this is simply a graphical scale, which shows, which area is 10m long. Again, in line with the resolution levels…

thank you for clearing the doubt