All kinds of vintage ad wrong here: the manic-eyed glee, the push to get kids to take laxative pills, and the supposition that a girl would be really happy to tell everyone that she has a dandy laxative tablet in her mouth.
From NLM (National Library of Medicine) via Pinterest
hold on
I think the joke is "it's so sweet the girl thought it was candy". It's advertising that the pill is sweetened, not chalky and nasty. The fact that she has a big storm coming is part of the humor




















