Mysterious Symbol Sequence

"Here's a word-based description: Two vertical lines, two empty squares, the letter 'm' repeated multiple times, followed by a combination of alternating squares and the letter 'm', with variations in the arrangement. The sequence continues with the letter 'm', empty square, repeating pattern of 'm' and squares, and additional 'm's. The description concludes with a series of empty squares, 'm's, and alternating squares and 'm's."