The mobile testing pyramid is a guiding principle for planning manual and automated mobile tests, breaking down testing into three layers: unit tests at the bottom, integration tests above them, and end-to-end tests at the top. To properly set up an environment for end-to-end testing, developers must automate their app processes, distinguish between automating their app and automating their testing, and build a proper E2E testing strategy that mirrors the user experience and doesn't get caught up in implementation details. Mastering the mobile testing pyramid helps create better apps, balance costs and time, and establish test coverage of the code base.