Petra is wearing the bigger size in the picture.
measurements flat measured in CM:
SMALL/MEDIUM
armpit to armpit: 50
shoulder to shoulder: 38.5
length front: 88.5
length back: 92.5
sleeve length: 49.5
waist: 52
LARGE/LARGER
armpit to armpit: 56
shoulder to shoulder: 42
length front: 107
length back: 111
sleeve length: 59
waist: 58