People may praise the talent of a painter capable of realistically portraying a scene and dismiss as artistically worthless the efforts of abstract expressionists, but obviously an exact replica of the scene depicted is not the only thing people appreciate in a painting, for otherwise photography would have entirely displaced painting as an art form.
Implied Rebuttal Conclusion
People are wrong to dismiss the work of abstract expressionists as artistically worthless.
Intermediate Conclusion
Obviously exact replication is not the only thing that people prize in a painting.
Evidence
If realism were the only thing that people wanted out of a painting, then photography would have entirely displaced painting as an art from.
Evaluate
The author proves her intermediate conclusion by showing that the negation of her conclusion would entail a falsity.
Fun language, right?
A lot of Method questions involve "Implications of Logic" type argument. An author might try to shoot down a claim by arguing like this:
Some say X is true. But if X were true, then Y would be true, which would require Z. Since Z is untrue/absurd, this means that we shouldn't believe X.
Other times (like here), an author will argue for the truth of a claim by talking about the implications of rejecting it.
X is true. After all, if it weren't, then Y would be true (which we know it isn't).
Goal
It will be hard to predict the language here, but it will probably be something like .