As Caitlyn Jenner continues to live out her well-documented gender transition, there’s one area in which she has returned to her heyday as Bruce Jenner, Olympic champion. Once again she’s a polished, effective pitchwoman, selling acceptance and transgender pride as capably as she once sold breakfast cereal.

Her new campaign continues on Sunday night with the premiere of “I Am Cait,” a glossy, eight-episode documentary series on E! from Bunim/Murray Productions, the reality powerhouse behind shows like “The Real World” and Ms. Jenner’s previous series, “Keeping Up With the Kardashians.” It’s the latest phase in a well-choreographed rollout that has included a two-hour interview with Diane Sawyer on ABC, a Vanity Fair cover and an appearance at ESPN’s ESPY Awards.

Based on that first episode, “I Am Cait” smoothly extends the resounding success of Ms. Jenner’s public transformation and cultural crusade — it accomplishes its inspirational, educational and motivational goals. (Later episodes were not available; presumably there hasn’t been a lot of time to film since Ms. Jenner began living as Caitlyn.) It doesn’t totally succeed as dramatic reality television, but perhaps that’s to be expected given how high the stakes are, both for the transgender cause and for Ms. Jenner’s personal brand.

Not a whole lot happens in the first hour of “I Am Cait,” and there’s not much to be learned for anyone who has watched the ABC interview. The main thing that’s new is the opportunity to see Ms. Jenner at length in full female hair, makeup and dress, and bounteous commentary is sure to ensue on her wardrobe choices — what do we think of the leopard number, the white pantsuit, the dark floral wrap? In one of the episode’s comic highlights, Ms. Jenner pulls an item out of her closet and her stepdaughter Kim Kardashian notes that Ms. Jenner’s former wife Kris Kardashian has the same dress.