Bold emphasis mine.
This is not a convincing argument because it doesn't consider why people consider loli a bad thing to begin with. It's the sexual attraction to childlike bodies and personalities that makes lolis disgusting. It definitely matters what the character looks like.
Wouldn't you think it's absurd if I grab some photo of a 50 year old milf pornstar and say she's actually 5 years old and if you find her hot then you're a pedo?
If some coomer jacks off to Yoko Littner, does he jack off to the idea that she's 14, or does he jack off to her body (which obviously does not look like the body of a minor?)
The fact that people meme about "oh she's actually 9000 years old" shows how flimsy of an argument is to think that it's only the listed age and not the physical appearance that matters.
I understand it's absurd, the thing with this viewpoint is it still presents a contradiction. Appearance and age both matter when we're talking about real people. However, if these rules only selectively apply to fictional characters, that means we are very likely to give passes to things that we shouldn't or prosecute people who don't deserve it.
If a coomer jacks it to Yoko Litter's 14 year old depiction, he is still jacking off to a drawing of a 14 year old. This is not okay. "She doesn't look like a minor" would not hold up in court, since it doesn't hold up for real people either.
This also opens up the can of worms of what "the body of a minor" means. Some minors are developed more maturely than others, what's the frame of reference then? You can't reliably establish one, apart from distinguishing a 5 year old from a 15 year old. Eventually the lines will get blurry in the range of characters 14 and up. Take for example Ilulu from Dragon Maid. Is it legal to coom to that thing?
If only the physical appearance matters, that also dismisses the personality and actions of the character. What if there's a character with the body of a 20 year old has their mind swapped with that of a 10 year old, shouldn't that character be considered pedophilia if sexualized? The character has no capability to consent, even if they have the body of an adult.
Different pedos get off to different things. For some it's the body type, others it's the power dynamic, etc. You have to prove beyond doubt that the images have no artistic merit and the person was getting off to it, and the only way that makes sense is to apply the same rules that real people follow to fictional characters...which still makes no sense! It's all contradictory.