A side photo is a model in profile, so it has no chest to measure: a sleeve print is scaled off the shirt's length between the shoulder and hem lines instead.
Drag the pink line to the bottom of the neckline — every “down” measurement starts there. Drag the black handles to the chest edges if the automatic fit is off. On a side view, the dashed lines bracket the shirt from shoulder to hem and the pink line is the shoulder seam. Arrow keys nudge the line you last moved; hold Shift for bigger steps.
Drop in a manufacturer product shot on a white background.
Pick the garments the heartandhook.com polo page should offer. You'll get one file with the cut-outs and their calibration — send it over and it goes live from there.
