My new project - four monk's robes. Two of them will have small garts under the armpit. The pattern is easy. A long rectangle for the body and a wide rectangle for the sleeve.
The sleeve prepared above should be sewn to the body to form this kind of cross. When sewing you should put it right side to the right side.
This happens when you seem to have a bad hair day. You may accidentally sew the garts to wrong sides (high rectangle instead of a wide one).
And if you are having a special bad hair day, after ripping the garts out and sewing them to the right place, you may sew them on like this.
Anyway, if you ever see a wrong side of a seam just next to the right side of a seam, you should stop to think for a moment:-)