Actually, I think Godwin's Law needs to be revised a bit WRT cases like this.

The original intent was to call out people who ratchet up the level of rhetoric in an online argument by comparing their opponent's position to that of Hitler or the Nazis. I.e., "Hitler also believed in gun control!", or "The Nazis would have loved to use abortion to eliminate unwanted races!".

But there is another way the Nazis can be brought into an argument, and that's what the person in this screenshot is doing. Specifically, he's using the Holocaust as a deliberately extreme example to show the person he's responding to that he or she really doesn't have it that bad after all. IOW, deliberately using the Nazis (an icon of evil in the 20th century) to immediately define the extremes and put other positions into a different perspective.

Not that this is always a valid technique (like Egress99 said, it's a bit overpowered for this specific case), but it can be. For example, if someone was questioning my support of the First Amendment, I might respond by saying, "Not true. I would defend even the right of Neo-Nazis to express their opinions." Some might cry "Godwin's Law", but that really doesn't apply.

On a side note, I've always felt that Reductio ad Hitlerum is horribly misnamed. I know it was probably meant as a bit of a joke, but it bothers me because its name implies that it is a derivative of Reductio ad absurdum, and the two really have nothing to do with each other. Reductio ad absurdum is, if used properly, a valid logical technique that can be used to great value. But Reductio ad Hitlerum is clearly nothing more than a shallow logical fallacy. If anything, the case I describe above would better be described as Reductio ad Hitlerum.