As you can see by the above screenshots, the first two images show the very outdated design that the app has been using since it launched. However, after the installation of version 2.5.001 things start to look more refined and modern.
In addition, there is support for a dark theme, which corresponds to the system theme. However, the app is still missing support for themed icons, joining the ranks of the YouTube Studio app, which for some reason has yet to be updated.