yeah i forget what the drawing textbook said... something like

typical height is between 7 and 9 heads tall, and if i remember correctly, typically the shoulders are equal to two heads width, this image you prompted clearly is wider shoulders than 2x this

there is a really simple set of body proportions rules that if you follow them your images of humans look realistic at scale

other non-humanoid bipeds have other ratios... elves are typically on the very tall end of the scale (9-10 heads) and the length of the neck, the distance from the pelvis that the hands reach to, and the position of the base of the pelvis relative to the foot-to-top-of-skull distance only vary by a limited proportion within human range and outside of this tends to be all kinds of spooks and ghouls