The Movi films in horizontal by default, but it can be used vertically as well

First, make sure Tilt Lock isn't enabled - if the padlock under Tilt is red, press it so it shows white and unlocked

Then simply turn the Movi 90 degrees and wait for it to re-align itself

When you've finished filming vertically, just turn the Movi back to switch to horizontal again

You can have the handle at the top or bottom in portrait mode - both work

To flip modes again, just turn the Movi back to horizontal