I think they're cute, but that's kinda irrelevant to whether or not the designs are valid or not.
Sidewinder disagrees which is fine, however if we're going to take this too seriously, how much sense does it make for Changelings to feed on love energy? honestly, I think it was basically a censored version of "life force" but obviously they cannot imply that too heavily in a children's TV show, so Hasbro had to come up with another description of what Changelings do to survive. But it's like Hasbro tried to have their cake and eat it too, design Changelings as predators, but did not wish to follow through with the concept even if it came at the cost of raising the age of the target demographic to at least PG territory, so we ended up with this, half in half out.
Love energy does not make a whole lot of sense to me, if Queen Chrysalis successfully found a lover to exploit, does that mean she can use them as a living battery continuously to grow infinitely stronger? the creepy implications that go with that, I don't want to get into, it's bad enough that Chrysalis tried to force Shining Armor into marriage, which I am sure is one of the things fans find scary about her.