1. A method comprising: receiving a markup language file, and a style sheet file containing breakpoints and a set of image display rules according to which image renditions of a first image are generated; displaying a first image rendition for the first image based on the breakpoints, the first image rendition having: the first image; and crop borders corresponding to the breakpoints; receiving an input indicating a modification to the image rendition; displaying a second image rendition that includes the modification to the first image rendition; amending the markup language file with at least one image display rule based upon the second image rendition, the at least one image display rule conforming to the set of image display rules; presenting on a user interface an option to select an image display strategy to be applied to the first image rendition; receiving an instruction via the user interface associated with the image display strategy, the instruction comprising one or more rules for scaling the first image, the instruction saved with the markup language file; generating a scaled image by applying the instruction to the first image rendition, determining a mismatch between scaled image and the breakpoints, wherein responsive to the mismatch being determined, presenting on the user interface an option to select a second image, receiving the selection of the second image, replacing the first image with the second image.