RST Engineering wrote:

I believe, but am not absolutely sure, that the aircraft in this picture is
at 10,100 feet. The hatched area disappears slowly as you descent below
10,000. At sea level it ought to be mostly gone.

Just the opposite, Jim. The pictured altimeter is near sea level. At
10,000 ft, the hatched area is mostly obscured.

Happy Flying!
Scott Skylane