• Step 1 -- Decision 1:  The law is probably not overbroad since it seems fairly specifically directed at prohibiting only material of a sexual nature as to be obscene (under Gulfport law) and, therefore, would not be used to prosecute other sorts of protected speech.  It is probably vague (under Connally v. General Construction 1926) because of the undefined term "implies sexual activity."  (This decision could go either way with an appropriate explanation.)
  
• Step 2 -- Decision 2:  Under Chaplinsky v N.H. 1942, this is the heart of the matter.  Is the picture obscene? (The appropriate category under Chaplinsky guidelines)   The evaluation of this case (go down on the chart) involves testing whether or not the picture can be restricted as "worthless speech?"
  
• Step 3 -- Testing the case against precedent:  Using the precedent case of Miller v California - test 1:  a shower scene does not seem erotic enough to be classified as "appealing to the prurient interest." [thus, not obscene]  test 2:  Under Jenkins v Georgia 1974, mere nudity is not enough to be considered "patently offensive and, thus, it is not obscene.  test 3:  Using the SLAPS test and the fact that the photographer is an award winner, this work likely has redeeming artistic value.  Thus, by failing at least one of the Miller tests, the work is not obscene and deserves 1st amendment protection.   [ You needed to cite Miller v California.  Citing one or more of the other cases is not required but does earn you some bonus consideration.]

   Resulting decision

• Due to vagueness  the law is unconstitutional (This could go either way with an appropriate explanation)
• The work is not obscene under Miller -- so (either way) McGahan's conviction is overturned.

Trudison v CIA

• Step 1 -- Decision 1:  The contact language Trudison signed (effectively the "law" to be judged in this case) is not vague.  It seems quite clear as to what the "rules" are.  While the language is broad in that it restricts any material concerning U.S. Government Activities, since it is in a contract Trudison voluntarily signed, that question should probably have been raised long ago by Trudison.  In any case, because it restricts discussion of activities but not opinions on public policy the court would not overturn the injunction based on over breadth.  (This decision could go the other way if you present a good justification.) 
  
• Step 2 -- Decision 2:  The book in question is certainly "worthwhile speech" since it deals with matters of clear public concern in the administration of government activities.  There is no indication of lewd, obscene, defamation or fighting words being at issue (as required under Chaplinsky).  Go up on the chart to "testing."
  
• Step 3 -- Testing the case against precedent:  The appropriate level one test is #2 - Balancing.  Is there sufficient government interest in national security to justify prohibiting the book?   Under Snepp v United States 1980, SCOTUS affirmed that secrecy agreements signed by government employees are binding and First Amendment protections cannot save the expression that is restricted under a valid contract.  In essence, the court in Snepp confirmed the lower court decision in United States v Marchetti 1972 that treated such conflicts as matters of contract dispute NOT free expression.  

   Resulting decision

• The injunction prohibiting publication is sustained.  [You need to cite Snepp v U.S. or at least U.S. v Marchetti.]