In a typical WordPress installation, the size of the
thumbnail image is 150x150 and
medium image is 600x400.
I'm theme developer and I have one client which has different sizes for these.
thumbnail size is 150x100
medium size is 300x200.
How can this be? Can this be overwritten in the WordPress core somewhere, or in the database?
My theme doesn't overwrite these but adds new/custom image sizes which shouldn't have any impact on the default ones.
I never faced this issue before. For all other clients, everything is working fine.
I would really appreciate some thoughts on this.