Can someone please explain what those are supposed to be?

It's konyakku, a food made from the konjac plant (aka Devil's Tongue) that has a sort of wiggly, gelatinous texture and consistency ... or so I've read. I've never actually had it myself. They're what Reimu ran into in the previous page.

Aaah okay, It looked like Karakasa's tongue to me in the previous page. I got it now.

Yeah, it did to me too and it actually took me a few passes to realize it. That was likely the gag - a sort of bait and switch situation.

and if i remember correctly theres a sex joke with the food right? something about a natural male enhancement