The provocatively named book “Hooker to Looker: a makeup guide for the not so easily offended” (video summary available here) gave rise to a dispute about the preemptive force of the Copyright Act, which the Fifth Circuit resolved in favor of preemption by looking to:

• Factual allegations. “Although Di Angelo muddles its complaint with contract allegations aplenty, it also alleges that it ‘acquired copyrights in the [B]ook’ by ‘writing, editing, planning and taking all photographs and making all illustrations, and planning, designing, and arranging the layout of the [B]ook.’ …  Although the complaint uses neither the term   joint work” nor “co-author,” it is nigh impossible to read Di Angelo’s allegations … without concluding that Di Angelo is alleging, at minimum, co-authorship of the Book.” 
• The parties’ contract. “The Contract does not define author, and the word’s common meaning can apply to multiple parties who collaboratively engage in producing one creative work, a possibility expressly contemplated by copyright law. And contrary to Kelley’s suggestion, the terms of the Contract lend some support to the notion that the Book would be produced collaboratively.” (footnote omitted).
• Requested relief. “[A] declaration of Di Angelo’s copyright in the updated work could permit it to exercise rights with respect to that work that it would not enjoy under the Contract. For instance, a declaration could allow Di Angelo to profit from the Book’s update, which according to its state court complaint, Kelley currently
  prevents it from doing.”

Di Angelo Publications, Inc., No. 20-20523 (Aug. 12, 2021).