。
The room is covered in trash.
Literal
Room [topic-は] trash-covered is.
~だらけ is a suffix meaning 'covered in, full of' — always with a negative connotation. ゴミだらけ (covered in trash), 間違いだらけ (full of mistakes), 傷だらけ (covered in scratches). Distinct from the neutral でいっぱい.