Hmm.... Two reasons I can think of for this happening are --
(1) you are growing this plant in a small container and fruit size miniaturization is taking place
(2) the seeds you planted came from a Hippie Zebra fruit that had set as result of accidental bee cross, most likely with a cherry tomato. Therefore, this is an F1 cross (Hippie Zebra x ???)
How do they taste?
Learning never ends because we can share what we've learned. And in sharing our collective experiences, we gain deeper understanding of what we learned.