I taught English at a middle school in South Korea. Although I didn't speak or understand Korean, I was still able to observe a lot.
I sat in the teacher's office almost every day and watched other teachers interact with each other. What I saw was no different than any other office.
I noticed teacher's who were confident, I noticed who was friendly, I noticed who liked each other, I noticed the conflicts and resentments -- I noticed their personalities, their disposition, and their day to day attitudes.
The reason I bring this up is because although I didn't understand the words they were saying, I was still able to get a good sense of who they were and how they were feeling through their body language.
That's why I bring up the mascot example. Mascots have infectious and engaging personalities. They're boisterous, gregarious and fun -- and we know this -- despite them saying anything.
Although I don't expect anyone to do jumping jacks like a mascot during their presentation -- the important point here is that body language communicates a whole lot -- people observe and take notice of it, especially when it comes to connecting and engaging with the people you're speaking to.