The two pieces seem to be located at a strong fold about 27” from the sealed end.
I get the impression the two pieces are meant to reinforce the bag at that point.
It isn't coincidental that they are placed where the long length of tape ends. The long length of tape (and the two pieces) reinforce 30.5" of seam.
The end of the long length near the "closed" end of the bag is reinforced by the triangular(ish) fold of paper and the strips of tape that hold it in place.
What is odd is that the seam to the left of the two pieces is not taped. About 6.5 inches of the seam is not taped. The only way the bag would be useful would be if it was folded at the strong fold where the two pieces are when carrying whatever object it was designed to carry.
The distance from this strong fold to the closed-end fold is 27".
The bag appears to be specifically constructed to carry an object (or objects) less than 27" in length.