It's easy to share your screen on Skype on a computer or mobile device, as long as you have a strong enough connection to support it.
To mirror your Android's screen, you'll need a Chromecast, a compatible TV, or a third-party app like Tenorshare Phone Mirror ...
Since I can't turn my ultrawide OLED by 90 degrees, my older monitor remains the only option when I feel like revisiting old games like Icy Tower and some old Pinball games. If you have an old monitor ...