I believe you're falling into a purely linguistic trap. In other languages we wouldn't even use the word "like" in this kind of constructions, that's an English thing because other wordings sound awkward, but I don't think it entails comparison.
In translations to Spanish, the article is titled "¿Qué se siente ser un murciélago?", literal word by word translation "What is felt being a bat?"
In French, "Quel effet cela fait-il d'être une chauve-souris?", literal word by word translation "What effect it makes to be a bat?"
In Chinese, "成为一只蝙蝠可能是什么样子", i.e., "To become a bat could be what feeling/sensation?"
None of these translations has a comparative word. And at least in Spanish (I won't speak about the other two because I'm not so proficient in them), using a comparative expression similar to "being like" in English ("¿A qué se parece ser un murciélago?") would sound awkward and not really convey the point. Which is why the translators didn't do so.
Of course I know that the original article is in English, but I think the author basically meant "What is felt being a bat?" and just used the "like" construction because it's what you say in English for that to sound good and clear. Your highlighted text could be rendered as "An organism has conscious mental states if and only if there is something that is felt being that organism – something that is felt by the organism." and it would be more precise, just doesn't sound elegant in English.