Customization and management of image sizes just got easier! Now in the image upload dialog you can set the max-width value for each image. Setting values for desktop and mobile means that your image is responsive—it will scale up or down as needed depending on the respondent's screen size.
Images can be defined as two unit types: pixels and percentage. To switch unit types, click the unit symbol/text on the right side of the input box. Note that using percentage means that the image takes up x% of the parent container's width. Read more about this in help documentation.
Lastly, the image settings dialog can be reopened to fine tune image sizing by clicking on the image in the text editor.