Lol. Drawn by Oda himself in an SBS:
Compare how they actually look:
Well, Usopp is masked above, so you can try the Wiki page for individual comparisons instead.
The female-ized Luffy actually looks a bit like this prank, which came out just after Ivankov’s Horu Horu no Mi gender-changing powers became known:
Some of the SBSes translated here.