Allow presenter to enlarge view of current shared screen

Currently when I am sharing my screen/document it pops up in a tiny box. If I'm hosting a video meeting that also has attendees in person, I'm unable to have the meeting pulled up on the conference room screen as the people who physically attend are unable to see what I am doing (the shared screen/doc is tiny)... but I'm also unable to see the attendees and chat if I pull up the screen/document I am sharing.