I got an email earlier today from Heritage Auctions touting its latest offerings, and the most interesting part of the message wasn’t the original art I could never afford, but an observation pointed out about a change made to the cover of Action #1 before the comic was released.

Here’s the published cover we all know.

But here’s the cover as it appeared in an ad in an earlier issue of Detective.

I wish I could find a better reproduction of the ad, but in any case—could you spot the difference?

At that size, probably not. But try again with a detail of the relevant section. First, the ad.

Then the actual comic.

Do you see it now?

Yes, that’s right! As Heritage noted, “the fellow in the foreground has just one sweat bead flying off of him, while in the final comic he has two.”

So between the time the cover of Action #1 was drawn and the time it went to press, a decision was made that a second bead of sweat was needed.

And it’s a good thing, too. For without it, kids might never have picked up the issue, Superman might have flopped, and for want of a droplet, the entire history of comics might have been forever changed!