A solid layer suggests water has collected and frozen, while loose frost can form from moisture entering the air space. The appearance is useful evidence, not a confirmed drain diagnosis.
What the observation tells you
A spilled container, defrost-water issue or another source may be involved. Breaking the sheet with a tool risks damaging the liner or concealed components. A drawer that is frozen to it should not be forced out.
A useful next step
Record where the ice starts and whether any package leaked. Protect food and use only the prescribed defrost process. Recurrent floor ice warrants assessment of the actual cause.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.