He’s saying that the spreadsheet represents the “picture” of the cat in terms of pixels and RGB values etc.
The algorithm/workers are not really “looking” at a picture of a cat, they are analysing and looking for patterns in the data that defines the picture of the cat.
It's obvious from context that it's the content of the media. To me at least.
If I play you a song on Spotify and say, "Is this a saxophone?", you wouldn't say, "No, it's a iPhone running Spotify."
If a policeman holds up a photograph of a person and says, "Is this the person who attacked you?", the victim doesn't say, "No, it's an 8 by 10 glossy print."
Yes but you had to think about it, as did I, and there was a moment where you went "hangon, did this person imply a spreadsheet could ever be a cat?" and thought you were 95% sure they did this very bizarre thing, it was distracting.
The algorithm/workers are not really “looking” at a picture of a cat, they are analysing and looking for patterns in the data that defines the picture of the cat.