said BBOX is a required parameter, so the following request is correct when I try to have clipped imagery according to the specified polygon axis.
WMS GetMap with BBOX and GEOMETRY=POLYGON
However, the imagery response is also available without BBOX parameter as following.
WMS GetMap with GEOMETRY=POLYGON
Then I found out there are tiny shape difference between them. What is this difference? Which one should we request for this purpose? If BBOX is not necessary, that would be convenient .