In technical pitch presentations, you often have to show the application through screen shots. While a picture of the application inside a monitor frame might look nice, it is a poor way to get your audience to see the content of the screen.
I would cut the monitor, cut the window bars above and below your application, and even zoom in to parts of the screen to highlight what is important. Cover everything that is not relevant (ads for example) with white boxes to keep things clean.
Having said that, there might be 2 uses for the monitor shot. One for a very quick 5-second slide that enables you to say “Let’s talk about the application” and move on. The second application is a slide that shows that your software is running on multiple platforms, but in that case you need a monitor image, a tablet screen shot, and a mobile phone application all on one page.