Is it possible to subset the image with the polygon shape (more than four edges) instead of polygon bounds using subset-operator/snappy?

The ‘geometry’ parameter is a bit confusing. You need to specify the name of a vector data node.
This needs to be created/imported first. To do this the Import-Vector operator needs to be used.
The format of the vector file should ESRI shapefile.

You can find example code here: