Measurement photos show a close-up of the ruler at the edge of the fabric for accuracy:
Shirts/Jackets: Photo 1 – Pit to pit (underarm seam to underarm seam); Photo 2 – Top to bottom (bottom of collar to hem).
Blazers/Sport Coats: Photo 1 – Pit to pit; Photo 2 – Top to bottom (bottom of collar to hem); Photo 3 – Shoulder to shoulder; Photo 4 – Sleeve length (shoulder seam to cuff).