As Kamala Harris prepares to take on Donald Trump, her advisers as Joe Biden’s vice president provide a window into her style and priorities.

Two threads are emerging in the short time since launching her White House run: Many Harris aides have worked primarily or entirely for her, not Biden. And she’s said to be considering several veterans from the administration of former U.S. President Barack Obama, who on Friday endorsed her, as well as some Biden-era heavyweights.

Harris trusts a relatively small group of staff that she sees as loyal, and that circle can change, including when particular subjects are dominating the news. Aides familiar with her working style say she prefers in-depth briefings, asks probing questions and wants to know about her blind spots. Some former aides conceded Harris is demanding, driven in part by high expectations and heightened scrutiny she faces as the first Black, woman vice president.