I think this is because photos from Earth are somewhat 'uniform', they're always the same angle, and because they're so far away, we basically always see only t

I think this is because photos from Earth are somewhat 'uniform', they're always the same angle, and because they're so far away, we basically always see only the day side from Earth, which makes them look a bit 'fake'. Meanwhile, the photos from the probes that actually went there are from more unusual angles and you can see some more amount of the night side. Similar to how images from something like the Himawari satellite (from geostationary orbit) quickly become a lot less visually interesting than photos from the ISS.