Is this cheating?

[Sumpter250]

The use of "photograph detail" has been around for as long as color photographs. This is where the "three foot" rule applies. At three feet, and beyond, it's extremely difficult to determine if the detail is actual, or photo(printed), and can be used with impunity. Just don't "overdo" it.
In cases closer than three feet, some detail can still be used, as in signs, curtains or drapes inside a window, cutouts for the windows of stores(mannequins, paintings, things that add interest but would be "models in themselves").
Photos/printed pictures, can be used close up with a little embossing to give them texture. If any of us has ever painted a backdrop, or used a photo backdrop.....we've "cheated". The only caveat is that we should never use photo/print, where it can easily be identified as photo/print. Embossing, cutout, and, where possible flat overspray all can make a photo/print harder to detect.
It's all part of the practice of deception, that includes vehicles with two "front ends"(or two rear ends), parked in front of a mirror so that the reflection looks like another vehicle, behind the physical one, or using forced perspective.
Limiting the line of site, helps these effects be more convincing.
Using photo/print, as a substitute for modelmaking, where the modelmaking would be the better choice, is cheating, kind of like (here's where I get slammed for my big mouth) using all ready to run!