Scorn quotes are a form of sarcasm or irony.
To use "scorn quotes" is to use quotation marks to indicate that the words enclosed in those quotes are to be attributed to someone else because the person making the quotation does not believe (is scornful of) the context in which the quotation was made.
E.g. Did you get to meet his "girlfriend"?
Do you think she was really a girlfriend?
The scorn quotes indicate that she was clearly not.