Answer
The pilot could misjudge the aircraft's clearance above the terrain and obstacles below it. The pilot should watch the terrain, plan obstacle margins, and avoid treating the displayed height as proof that the aircraft is safely separated from everything below.
Explanation
Many aircraft displays reference the takeoff point. That value can be useful, but it does not show how close the drone is to rising ground, trees, towers, or buildings. Safe height management combines rules, terrain, obstacles, and aircraft performance.