When you search for multiple events (e.g. clicked x AND visited page AND etc.) and those events occur in separate sessions, the results will display a clip rather than a single session.The clip will contains short vignettes of time surrounding the searched event where you'll see a few seconds before and a few seconds after each matching event.
When you're watching a clip, you'll notice breaks in the session playback line. These breaks indicate a 'time warp' within the playback, wherein the playback is transitioning from a matching event in one session to the next matching event and session.
Don't worry, you still have the ability to view the entire session. You can choose to jump into the session where the clip begins or continue playing from where the clip ended by choosing "Watch the full session" or "Play on" in the events bar: