Katy Perry's performance during halftime at this year's Super Bowl is still reverberating at the U.S. Trademark Office. On Friday, the pop singer got the bad news that her company's initial attempts to register a "Left Shark" design had been rejected.

During her halftime performance, Perry had social media buzzing as she danced with two background dancers dressed as sharks. Many were talking about the shark on the left — actually, Perry's right — who seemed to be deviating from the choreography.

"Left Shark" became an Internet meme after the Super Bowl, and Perry's attempt to capitalize on it included a registration on the shark design as well as on the phrases "Left Shark," "Right Shark," "Drunk Shark," and "Basking Shark."

David Collier, the trademark examiner, isn't yet impressed by the attempt to register the design, which, he wrote, "identifies only a particular character; it does not function as a service mark to identify and distinguish applicant’s services from those of others and to indicate the source of applicant’s services."

In other words, there's not enough evidence submitted yet that consumers look at "Left Shark" and think of a Katy Perry music performance.

The examiner also noted the differences between a photograph of Perry dancing with "Left Shark" and the drawing of "Left Shark" submitted as the design.

"Specifically, the [photograph] displays the mark as a stylized depiction of a forward leaning shark in nearly a front profile with a portion of a dorsal fin, two pectoral fins and two legs and feet substituted for the caudal fin on the tail," he wrote. "The shark has five gills, a full mouth with teeth and round eyes with eyelids; however, the drawing displays the mark as a stylized depiction of an upright shark in full front profile with no dorsal fin, two full pectoral fins and two legs and feet; the shark has three gills and the shark's mouth appears without teeth; the shark also has oval eyes without eyelids."

Perry can try again, but at least she's had more luck with registering the word mark "Left Shark." The examiner did ask for a bit more clarification on the identity of goods over which she's attempting to assert dominion. For example, Perry's company says "costumes," but does she mean Halloween costumes or dance costumes? She says "figurines," but can she be more specific by saying, for example, "modeled plastic toy figurines"? Despite these minor quibbles, though, Perry's on the way to having the registration published.

The mixed success comes after Perry took on one designer named Fernando Sosa who attempted to capitalize on the phenomenon by selling a 3D-printed figurine of "Left Shark."

Perry's lawyers quickly sent a cease-and-desist letter that stated, "As you are undoubtedly aware, our client never consented to your use of its copyrighted work and IP, nor did our client consent to the sale of the infringed product. Your unauthorized display and sale of this product infringes our client’s exclusive rights in numerous ways."

Sosa then retained an attorney, Chris Sprigman, who retorted that costumes are "generally not copyrightable" and asked why "Left Shark" should be treated differently.

Steve Plinio, the Greenberg Traurig attorney representing Perry, responded that Perry's team created shark drawings in the process of designing the costumes, and that those costumes were copyrightable.

Sprigman then volleyed back that the drawings were irrelevant — the sketches might be copyrightable, "but that doesn’t make the Left Shark costume copyrightable."

That discussion mostly centered on copyright, which protects works of authorship, rather than trademark, which protects the phrases and images that identify and distinguish the source of goods and services. Stated another way, holding a "Left Shark" design copyright would allow Perry some ability to prevent others from creating derivatives, while holding a "Left Shark" trademark would allow Perry to attack those who would mislead the public into thinking she's behind their "Left Shark" endeavors.

Meanwhile, Perry isn't done with "Left Shark" at all. Here's a picture she put up last week on Instagram.