I absolutely despise how online retailers have always allowed sellers to use the most nonsensical classifications for certain item categories, to the point most categories' filters are fucking useless
"User experience? Lol fuck that, browse endlessly you fucking peon!"
Everyone has their own way of doing things. In order to integrate them, you have to create your own way of doing things. Later, other people have to integrate your new schema with their own. It's just the nature of working with many different companies
Impossible to say how the screenshot came about. At some point, the semantics of someone's data was misinterpreted. Something was called a hard drive when it isn't, something was treated as a capacity when it isn't
Just as a matter of interest, at the time of the screenshot I opened one of the "chickens" results and combed the page but failed to find any instance of the word (singular or otherwise). Today and yesterday, several people have asked me for the "chickens" results, which are sadly fewer now; however, one still exists within the constraints of the filters I applied. I still can find no instance of the word on the product page.
I'm sure the word "chicken" appears somewhere in the metadata, but it's still a failure of the system and the UX.