Is Grotesque Subjective?

In the process of describing what grotesque is in her essay The Grotesque in Southern Fiction, Flannery O’Conner mentions the fact that a Northern reader might find something that is grotesque to them when it is a part of the norm in the South.

“… I have found that anything that comes out of the South is going to be called grotesque by the Northern reader, unless it is grotesque, in which case it is going to be called realistic,” (O’Conner 815).

            I feel like this begs the question: is grotesque, ultimately, something that depends on the readers? A possible follow up question would be: is it possible to make something that is a part of a normal setting grotesque? It would seem to me that the answer would be yes to both questions but I am not entirely sure. I see that O’Conner is definitely aware of the fact that the readers do have a hand in the matter.

“Even though the writer who produces grotesque fiction may not consider his characters any more freakish than ordinary fallen man usually is, his audience is going to; and it is going to ask him, or more often tell him, why he has chosen to bring such maimed souls alive,” (O’Conner 816-817).

            O’Conner mentions the fact that a grotesque writer would achieve their means through way of distortion of their characters and/or real life. This distortion can reach a point where anything after it would be considered too much even for a Northerner, apparently.
            So, with this everything in mind, I go back to the questions I have and still contemplate them. Even though it would be easier for a Northern reader to find something grotesque, is it possible for something be grotesque in a setting that it normal for some readers? Certainly not everything would be considered weird for the reader but possibly some of the events/actions could set the tone for the whole book so that it can be considered grotesque fiction.