I consider the Gemba walk an Agile leadership practice because it requires a manager to interact with the teams who are doing the actual work. It is done in order to understand how value is delivered to customers and other stakeholders. And the goal is to find out how to help improve the system in which the people are doing their work.
On the other hand, I consider performance appraisalsnot an Agile leadership practice. Because research shows that such appraisals hurt people and their interactions. And they have nothing to do with delivering value to customers, or any other stakeholders. And performance appraisals are usually misguided in the sense that they attempt to improve people, instead of the system.
p.s. I call them Agile leadership practices, and not Agile management practices, because you don’t need a management position to start applying most of these practices. Nobody needs anyone’s permission to be an Agile leader.