In a nutshell, the courts have told us that they are not stupid, and what is obviously a pretext to avoid obscenity law, like adding a Supreme Court case to an otherwise obscene work, is not enough.
Works are judged as a whole under Miller, and something in the nature of slap-on label does not add to what the work fundamentally is.
The most famous articulation of that is found in Kois v. Wisconsin,
http://www.xxxlaw.com/cases/kois.html a per curiam decision of the Supreme Court in 1972, involving a Milwaukee underground newspaper (one that I grew up with in Milwaukee) name Kaleidescope, which featured poems about sex next to pictures of people fucking. The Supreme Court considered the possibility of pretext to try to slip obscenity through, famously saying, "A quotation from Voltaire in the flyleaf of a book will not constitutionally redeem an otherwise obscene publication, but if these pictures were indeed similar to the one seized - and we do not understand the State to contend differently - they are relevant to the theme of the article. " They reversed the conviction without even requiring the defendant to file a brief. A "per curiam" decision means that no particular justice wrote it. It is the words of the whole court.
You can read my observations about that case (and others) at
http://www.xxxlaw.com/cases/index.html.
The question of just exactly a "work as a whole" is on the internet is a question not fully resolved, In both Extreme Associates and in Max Hardcore, individual clips were charged, under 30 seconds in duration, extracted from much bigger websites. The best insight into the subject comes out of a case involving magazines from the Fifth Circuit, McAuliffe.
http://www.xxxlaw.com/cases/penthouse.html