The perfect run video does not give a correct solution to this puzzle, as their solution is based on luck with timing and will likely end your perfect run. The developer posted the actual solution in the comments of that YouTube video, so credit for this solution goes to them.
This is done immediately after your character says the line "Are those... are those my hands over there? How did they get there?".
Wait Front, Forward, Forward, Marker A, Turn Right, Wait Front, Turn Right, Forward, Turn Left, Turn Left, Forward, Go To A