Resolusion very coarse

My name is Tetsuya.
I have made a ortho photo,and download it.
but my ortho photo have very coarse!!

setting as follow for processing

Export Type: 2D Map
Resolution: 2.00 centimeters per pixel
Map Projection: Web (Web Mercator/EPSG:3857)
File Type: GeoTIFF
Single Image?: False

I think this ortho photo’s resolution is about 10 centimeters per pixel. very coarse.

I have a no problem take a picture(hight,corse).
I think something have wrong in setting or not.
Prease give me a advice.

I am japanese.SO not native for English.