What Both DSLR and Mirrorless Cameras can do:
Lenses: Both DSLR cameras and Mirrorless cameras can have inter-changeable lenses. This can allow users to purposefully select and switch out the lenses for different effects.
Image Sensors: Both types of cameras can have large image sensors to allow them to produce very high-quality images. They are relatively similar to each other in sensor size too (unless you want to spend upwards of $2,000 for the camera body alone, which gives you the larger sensors.)
Prices: Prices are comparable between an entry-level mirrorless digital camera and an entry-level single lens reflex digital Camera.
Manual Settings: Since both types of cameras can be fully manual, you have the chance to learn how to use those features to your advantage and create those beautiful blurred backgrounds (bokeh - see example below) that everyone loves so much.