As development progressed, WordPress’ design and branding took shape. Some of the first lengthy discussions about WordPress’ look and feel happened on the wp-design mailing list. This was a private mailing list of designers and developers interested in crafting WordPress’ aesthetic. Michael Heilemann (michael), Khaled Abou Alfa (khaled), Joen Asmussen (joen), Chris Davis (chrisjdavis), Joshua Sigar (alphaoide), and Matt composed the main group.
The first focused design discussion was about WordPress’ logo. Matt designed the original logo; it was simply the word “WordPress” in the Dante font:

Since the project was so small, community members had fun on the homepage, riffing on the logo with versions for seasonal holidays, birthdays, and other events.

Eventually, WordPress needed a professional logo. Usage was growing and WordPress needed a logo that properly represented it. As a free software project, the community was the first place to look for a logo. Community suggestions were solicited. A mixed set of results came back, which were shared with the wp-design group for feedback.
The first suggestions were from Andreas Kwiatkowski:

A second batch came from Denis Radenkovic:

Logo feedback was mostly lukewarm, though some of the designers liked Radenkovic’s heart logos, describing them as “instantly recognizable.”
The heart logo was iterated on, with another version posted to the design mailing list:

A version of the admin screen with Joen Asmussen’s hear logo in situ was produced:

Community members weren’t the only ones tackling the logo. In March, Matt met Jason Santa Maria at South by South West and asked him to try redesigning the WordPress logo. They shared ideas about what they thought the logo should be: “the things that kept coming up were not only the idea of publishing but the idea of having a personal journal and a personal thing that might have some sort of tactile overtones,” Jason says. “We were making links to things like letterpress and journaling and any sort of older representations of what it meant to publish something in a physical form.” In April 2005, some of the early versions were shared with the wp-design group:

There were a number of responses from the designers on the mailing list: “a little too aristocratic” was one of the comments. The designers felt that Denis Radenkovic’s design was more in line with WordPress’ brand.
More designs were posted to the group:

The members of the mailing list didn’t seem to agree on WordPress’ aesthetic. On one hand, there were people who felt that the logo should represent warmth and community, and on the other hand, something classic and elegant. To reach a consensus, discussions happened offline. Khaled reported back:
WordPress is meant to be the Jaguar or Aston Martin of Blogging tools. […] that line sets the stage for what the design of the branding should be. Elegance, polished, and impecably [sic] designed is where we should be aiming.
The logo was finally decided on May 15th, when Matt sent an email to the mailing list with the subject “I think this is it.” Matt’s message contained just one image:

The major change to the logo, other than the new typeface, was the mark. The creation of a mark gave WordPress a stand-alone element of the logo which, over time, would be recognizable even without the word beside it. This could and would be used in icons, branding, and t-shirts. It’s become instantly recognizable, helped by its appearance on WordCamp t-shirts the world over.