Images can be placed in both the header widget and the image widget.

When your image contains text, it is advised to use the image widget: it is scaled according to the screen dimensions on mobile devices.

The images used in the header widget, are in most cases cropped for mobile representation. In this case, you run the risk that the text will not be fully visible. You can use the 'safe area mobile'.

Find detailed information about the use of these widgets, safe area mobile and dimensions in this designer manual.