Lol I hope though you didn’t pull several all-nighters trying to solve the case .

But this said, yes you’re right, it is her earlobe indeed, with a pink so pale that it seems to be white, the same white they used for her gloved hand.

And personally, I have now decided that a six-fingered Sailor Moon will be my new headcanon. On each of her earlobes grew an extra finger for her 30th birthday :p .

The coloring is so pale that it does appear she has an extra finger, but that “finger” is actually her earlobe.
And instead of Usagi making a rude gesture as it first appears, she’s in fact doing her famous two-finger pose aka the Batman aka the V for victory aka sideways peace sign.

The hand is drawn at a really awkward angle, but I’m sure this is what’s intended. The faint coloring makes her earlobe appear as white, so it causes even further confusion!