On dense green embroidery, the upper-left tuft and the lower-right tuft both stay under your fingers. Each side offers its own pull. Only when both land in the same window does stitch-light creep outward. A slipped tuft snaps the thread, and a mistimed pulse snaps it faster. Sheets differ: some swap corners halfway, some hide a nail you must not touch. Dark stitches fill the cloth. Two hands listen apart, rather than one finger chasing a dot. When the moss reaches the frame, that sheet is woven.
Hold both moss tufts and match their separate stitch beats.