Unusual denim jacket with crotchet sleeves

Meant to look like a denim vest with sweater underneath, but is actually one piece. 2 pockets on each side, one zip the other button. Sleeves are very long for some reason so I’m wearing them rolled up in photo. Only worn once but has some pilling on the underside of each sleeve ( see next to last photo). From PacSun. Detachable hood which snaps in. Says Size L but I’m a S- M and it’s snug on me.