I wouldn't call it sarcasm, to be honest. From Wikipedia:
Dramatic irony contains elements of contrast, but it usually refers to a situation in a Greek play where a character who is omniscient watches over a less educated character as that character experiences a situation or event that is of lesser significance than that character realizes.
Dramatic irony contains elements of contrast, but it usually refers to a situation in a Greek play where a character who is omniscient watches over a less educated character as that character experiences a situation or event that is of lesser significance than that character realizes.