SAN FRANCISCO—A high-stakes gender discrimination lawsuit that has made waves in Silicon Valley took a sharp turn Tuesday as defendant Ellen Pao went on the defensive against her former employer's lawyer.

Pao, Reddit's interim CEO, who is suing storied venture capital firm Kleiner Perkins Caufield & Byers for $16 million, took the stand for the first time on Monday and Tuesday as the trial entered its third week. She spoke articulately in an even tone as her lawyer, Therese Lawless, led her through a year-by-year breakdown of her turbulent time at the firm, her work experience and the fallout of her 2012 dismissal.

But Pao's testimony tensed up when KPCB lawyer Lynne Hermle launched into her cross-examination on Tuesday afternoon with a torrent of caustic questions. Pao returned them with clipped responses after long pauses, her tone often taking on a hostile edge. Her composure was a marked departure from earlier in the testimony when she rarely hesitated.

Pao's public speaking skills are in fact on trial here. KPCB's defense has painted her as "quiet" and unable to "hold a room," while her lawyers have touted her masterful speechwriting abilities, which were part of her job description when she first signed on at KPCB. The defense is using this characterization to chip away at Pao's claim that she was unfairly denied promotions because of her gender.

Criticized for being arrogant

Hermle first took aim at her work experience. She pointed out that Pao lacked any investment experience when she joined KPCB and that she had never started or incubated a company. Hermle played a video clip from the pre-trial deposition in February to show Pao was not looking for a longterm investment role when she joined the company, contradicting what Pao has said about her goals at the company. In the tape, Pao said she was just looking for an "interesting job."

Hermle ran through words listed in Pao's original job description to try to back up defense claims that she was not promoted because she was arrogant and dismissive.

“You understand what humble means, Ms. Pao?" Hermle asked in reference to the description, to which Pao responded that she did.

While a good portion of Pao's testimony on Monday centered on her criticism of the "loosey-goosey" HR policies at the firm, Hermle used deposition tapes to establish that Pao had never asked anyone at KPCB if the company had an anti-discrimination policy. Pao said on the stand that she had asked for the policy in 2012, but Hermle shot back with a deposition clip of Pao admitting that she never did.

Brushed off complaints

Earlier that day and on Monday, Pao described how her complaints about gender bias were repeatedly brushed off by senior employees at KPCB and talked of how she persistently lobbied for more HR infrastructure.

Pao testified on Tuesday that Stephen Hirschfeld, the investigator who conducted a 2012 internal probe that cleared her complaints of sexual discrimination, was antagonistic and constantly pushing her to give company-friendly answers. Pao said the company's CFO told her that he was interested in a job as the firm's human relations lawyer.

Pao claimed she sued KPCB only because she had exhausted every avenue for complaints within the company.

"I had gone through every possible internal process I thought I could go through...Kleiner Perkins did nothing," she told the jury.

The affair

Hermle also dug into Pao's months-long relationship with her colleague Ajit Nazre, who she claims undermined her career in retaliation for her ending the romance. Hermle delved into months of emails and text messages exchanged between the two throughout their 2006 relationship.

Pao claims the tryst started after Nazre pursued her aggressively, and she only relented when he told her that his wife had left him. When she found out that he was not separated with his wife, she was furious and broke off the relationship, she said.

Hermle homed in on a business trip that the two took to Germany in 2006, where Nazre allegedly hit on her for the first time. She said she did not refuse his advances the first time because she was "in a daze" after she was hit by a taxi. Nazre confirmed to Hermle that she did not explicitly make it clear to Nazre that she was not interested in the advances.

Hermle displayed flirtatious messages from before and throughout the relationship to poke holes in Pao's claims that Nazre aggressively pressured her into the affair. Their conversations showed that the two had said they loved each other and talked of marriage and children, and Pao said she would wait a year for Nazre to get divorced.

Pao said she wanted to ask KPCB for a big enough sum of money to "hit their radar" when she began exit discussions in 2012. She said she thought around $10 million would do.

"I wanted the payment to be big enough so that it will be a meaningful number, so that it will show them that it was actually painful to not fix problems," Pao said.

Reddit paycheck v. KPCB paycheck

The testimony also covered details about her current post at Reddit. Pao said she started out as a consultant for the company making around $600 per hour. She later signed on as senior vice president of business development with a $150,000 starting salary, which was increased to $250,000 after she was bumped up to interim CEO.

At KPCB, Pao had a base salary of $400,000 not including bonuses. But she stood to gain up to five times that number had she been promoted to senior partner.

When Lawless asked her why she had pressed on with the suit despite landing a lucrative job at Reddit, Pao took an uncharacteristically long pause before delivering a sweeping statement about gender equality in venture capital.

"It’s been a long journey, and I’ve tried many times to bring Kleiner Perkins to the right path," Pao said. "I think there should be equal opportunities for women and men to be venture capitalists. I wanted to be a VC, but I wasn’t able to do so in that environment."

The trial will pick up again Wednesday morning with more cross examination.