The differences in MX Brio and Brio 4K are the following:

• MX Brio has better image quality in low light or difficult lighting conditions.
• MX Brio uses a Sony Starvis sensor that has 70% larger pixels than Brio 4K. 
• MX Brio uses AI face-based image adjustment that results in a tailored improvement of the image quality while Brio 4K uses a centered image adjustment.
• The adjustments possible on the software are much more precise and complete with MX Brio. You can even adjust Tint and Vibrance, which isn’t available for Brio 4K.
• The privacy shutter in MX Brio is integrated vs attachable on Brio 4K.
• MX Brio has an accelerometer that allows you to switch the view in Show Mode by tilting the camera.