Change Artboard Name
At the top of the artboard, you are able to edit the name of each artboard.
Change Artboard Background Color
Click the color tile at the top of each artboard to change the background color of the artboard.
Change Artboard size
Click the aspect ratio at the top of each artboard to change the size of the artboard.
Size can be different among different artboards.
*Note: You cannot launch an experiment if it contains artboards whose size doesn't belong to the platform you choose to launch.