According to release note it should be possible in Jira 8.1 to resize the deteiled view in Kanban boards. We just upgraded from Jira SW 8.0.2 to 8.2.4 and it is not possible to resize the deteiled view in Kanban while in backlog it is possible.
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events