"Device Mode" is a feature of Chrome DevTools that helps simulate mobile devices, and is used to check the display and behavior on different devices such as smartphones, tablets, and desktops.
The mobile execution environments provided by Autify include “Emulator (Rapid execution)” which uses this Device Mode.
Please refer to the screenshot in “Supported OS and browser versions (mobile)” for the devices available in the Emulator.
For more information on Device Mode, refer to Chrome for Developers documentation.