Flattering Maroon Aerie Turtleneck - Size Medium but fits like a Small

Very flattering fit for this maroon Aerie Turtleneck. Would love this in another color but maroon just doesn't look great on me. Fits as a size small but is listed as a medium. Very soft and comfortable. Can be dressed up or down. I actually wore this for a job interview under a blazer (and got the job!). Only worn a handful of times. Body length (shoulder seam to bottom) = 25" Body width (armpit to armpit) = 15.5" Sleeve length (top of sleeve to shoulder) = 26"