Wispy in its first season, “Doll & Em” somehow got even thinner and less substantial in its second six-episode run. Pairing actress-writers Emily Mortimer and Dolly Wells in a vehicle for the U.K.’s Sky on which HBO has partnered for what amounts to a pittance, the series again focuses on how their professional relationship tests their personal friendship, only this time, in an even less-convincing venue. The pair’s core affinity seems sweet and real enough, but the show comes across as a vanity project, with celebrity cameos that feel like little more than “look who we could get to pop by” name-dropping.

Season one had an interesting but ultimately weak premise, with star Emily hiring best pal Dolly to serve as her personal assistant during a movie shoot. The fact the two didn’t realize how that subservient relationship would test their bond simply didn’t ring true, but did produce some funny and heartfelt moments along the way.

This time, with Dolly having emerged as an actress in her own right, the duo have pushed their collaboration into a new realm, writing a semi-autobiographical off-Broadway play together loosely based on their shared history. Yet the prospect of a major movie role makes Emily reluctant to star in it, to Dolly’s dismay, forcing them to recruit actresses (Olivia Wilde and Evan Rachel Wood, as method-acting caricatures of themselves) to fill their shoes.

Too often, “Doll & Em” feels like a poor man’s (or woman’s) version of Ricky Gervais’ “Extras,” providing a rather jaundiced Brits-eye-view of showbiz. That includes Ewan McGregor showing up to earnestly read his awful, dark poetry, and Mikhail Baryshnikov providing the theater where the production is to be staged.

As with the L.A.-based first season, Mortimer, Wells and director Azazel Jacobs have fun with the fish-out-of-water aspects of placing the two in New York (Dolly can never quite get her GPS to function properly). Still, even the material about two people who find their ties strained by being at different stages of their lives — Emily’s married with kids; Dolly’s single — feels tired, which unfortunately counterbalances the quality performances and the stars’ natural, real-life rapport.

Given what HBO invests in some of its original programming, the network should be cut some slack for taking fliers on the occasional less-expensive project, especially with the potpourri of admirable British series from which to choose. But the pragmatic nature of that approach doesn’t make this show any more compelling as a viewing proposition.

In the aforementioned “Extras” and “The Office,” Gervais established a structural template for these quick-hit, bittersweet comedies, with a couple of short seasons and a wrap-up special. In hindsight, skipping the buildup and jumping directly to the Christmas episode probably would have better served “Doll & Em.”

TV Review: ‘Doll & Em,’ Season 2

(Series; HBO, Sun. Sept. 13, 10:45 p.m.)

  • Production: Filmed in New York by King Bee Prods.
  • Crew: Executive producers, Andrew Eaton, Lucy Lumsden; producers, Alessandro Nivola, Kevin Comer; director, Azazel Jacobs; writers, Emily Mortimer, Dolly Wells; story, Mortimer, Wells, Jacobs; camera, Tobias Datum; production designer, Caroline Foellmer; editor, Darrin Navarro; music, Mandy Hoffman; casting, Nicole Arbusto. <strong>25 MIN.</strong>
  • Cast: Emily Mortimer, Dolly Wells, Olivia Wilde, Evan Rachel Wood, Ewan McGregor, Mikhail Baryshnikov
  • Music By: