Prickly Pear
Half the fun of going grocery shopping is getting to buy things that you’ve never tried before. The other half is… well… there is no other half. Grocery shopping is a boring chore. Anyway, this person got to test out a sample of what appeared to be some sort of fruit. Before popping it into their mouth or asking the sample-hander-out-er what it was, they shared the picture on Reddit to seek answers.
The OP’s guess that it was a cactus-like gummy candy was pretty close to the truth. This is actually a piece of prickly pear, a type of edible cactus fruit. If you’ve watched Jungle Book, you’ll know that it’s Baloo’s favorite snack.