A local pattern may relate to that drawer's loading, closure or nearby airflow. It provides more useful information than saying the entire freezer is iced up.
What the observation tells you
Check whether a pack projects behind the drawer or whether its front seats differently from the others. Do not remove fixed panels to follow the ice deeper into the cabinet. Uneven frost does not automatically identify a faulty fan or sensor.
A useful next step
Record the drawer position and the condition of adjacent compartments. Follow owner-care guidance for safe frost removal, and report recurrence or unreliable temperatures after the correct arrangement is restored.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.