title: Possible to change the preview screen size?
body: <p>i have my gutenberg custom block previewing ok but i was wondering if there was a way to override the size of the 'hover preview window' as currently it's displaying the mobile styles for the block and not the desktop styles.</p>
  <p>please see image for reference.</p>
  <p><a href="https://i.stack.imgur.com/7OUHb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/7OUHb.png" alt="enter image description here" /></a></p>
  <p>I ideally would like the preview image to be landscape rather than portrait, any help would be much appreciated!</p>