I'm guessing that it's giving you that kind of image because usually photograph captions don't use keywords like "photorealistic", it's mostly when you're doing illustrations, concept art and similar, that you use it to convey it's trying to imitate a photo. So it's creating images that look like those images, rather than actual photos.

Here is "Create four photographs of a cat": https://imgur.com/a/dRlCwqy

Iteration "Make the photos more realistic so they look like pictures taken with a real DLSR camera": https://imgur.com/a/WX0LEjD

Seems to produce OK results.

This one, to me, could be mistaken for not only an actual photo of a dog, but my own dog. (aside from the cyborg implant, which is a bit of a giveaway :) )

https://www.karmatics.com/stuff/cyborgdog.jpg

I didn't even bother saying "photorealistic", but I did give lighting hints:

"tricolor english shepherd future cyborg parts on head and front leg, very futuristic tech, replaces side of head and eye, black anodized aluminum, orange leds, big raised camera eye where normal eye would be, with colorful rich deep teal artificial iris, in worn future urban park with pond and stone bridge but pretty near dark with streetlight above beautiful dog and technology"