Tips on iFrame Codeing
Here is how you can select the orientation and ratio of the brain.
Simply insert, right after the brain reference and before the quote, ?ratio=60&orient=h if you want an horizontal split and a ratio of 60% plex / 40% notes.
You should end up with something like this (bold is code to insert):
<iframe width="800" height="600" src="https://app.thebrain.com/embed/cb759044-6685-1234-1234-1234567890?ratio=60&orient=h" frameborder="0"></iframe>