Is this vertical?

Sometimes I'm not sure about things.  When I started this, I thought oh, this would be great if it were vertical.  But after I finished it I had to ask myself, is it vertical???  Does vertical mean it's straight up and down, or does it mean it's just not horizontal?  I know this isn't horizontal so it's vertical - right???? Help me solve this debate (even if it's just a debate in my mind) and let me know what you think.