What is the case here? Does he/she imply that there is blood over his/her arm ( Maybe (s)he's cut it with sth.) or there's blood inside vessels in his/her arm. Since "zitten" is used, I tend to understand that there's blood over his/her arm. Maybe (s)he's a butcher. :) Thank you.
In a post elsewhere there is the explanation that zitten indicates containment. That doesn't apply here as the blood is on the arm. So is it correct that zitten doesn't always mean containment? Could 'een kat zit op de bank" for example? The opinion of a native speaker would be much appreciated!