In the scene when Nick and Reagan are arguing about her promotion, you can see Nick speaking and Reagan scratching her back on the left side with her right hand. The scene cuts to Reagan's front view and you can see her hands folded in the front and when the scene cuts back to Nick speaking and you can see Reagan's moving her right hand from her back after scratching it.
When Winston is recording his fake radio show he is shown talking into the top of the Blue Yeti microphone which is a side addressed.