It looks like that ID would apply to the div itself. In the case of the sample app, the ID is actually #ZoomEmbeddedApp. When testing with that ID, I saw that I could change the #ZoomEmbeddedApp > #zoom-sdk-video-canvas and the related elements inside to change the size of the window.
However, I’m thinking there is some flexbox tricks that we could use here but I’ll need to check with our team. Trying to set the flex property didn’t yield any results.
Can you send a screenshot of what you’re seeing? What browser is this with?
Max