You’re are missing the point entirely of what everyone is saying and what nobody said.
Nobody said the design wasn’t import or less important, that would be totally moronic and it weird you would assert that given it’s not mentioned once for obvious reasons - it goes without saying!
I spend days on my designs, as do many others. I spend kg’s of material testing how things work and how they could be better designed or print settings changed to guarantee success.
Your question was about “why should we have to provide a photo” and everyone said because it makes sense and in reality its required as proof that your design works.
The annoying truth is; many ‘designers’ aren’t designers, their thieves, either of other people’s time, energy and filament because their designs are rubbish and never tested and/or they stole the work and have no idea how it should be printed as they never designed it.
If your designs are so simple that an idiot could print them - great, well done, whatever noise people need to make you happy that you are a genius amongst us.
Yet, most designers aren’t geniuses who can nail their simple or complex work first try and take the pride to ‘taste the meal they cooked’.
A photo is the evidence that your design does exactly what is says on the tin.
I don’t know how many other people need to say the same thing to you or in which other way to say the same basic thing - provide a photo!