Did you see it? Well, let me help you out.
These two panels are supposed to take place in sequence:
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See it yet? Look carefully now.
No, look at what Rorschach is wearing.
There you go: How did Rorschach manage to get his mask back on between those two panels?
Once I start thinking about stuff like that, I just can't enjoy the joke. So, to help make this funnier, which is what I do here at the BTTISB, Let's take a look at it this way:
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Isn't that much better? Now, I get it.