Images that uploaded via fields on an element cannot be resized at this time. However, if your goal is to provide information/instruction about a view, you can use the information panel in the view options:
Images in the information panel will attempt to size to the width of the panel or two the native size of the image, whichever is smaller.
Kent
Christina
Is there a way to resize images when they appear in the info panel on builder? When we add an image it's too small to be useful.