"Fit to Frame Proportionally" is a very nice feature in FrameMaker which allows the user to have an image in an anchored frame fit to the frame proportionally.
This feature is a one way road however. If you use it and the stretch the image and again the use "Fit to Frame Proportionally" FrameMaker does not remember the original dimensions of the image. It would be optimal if "Fit to Frame Proportionally" was a property assigned to the image remembering and reading the proportions of the original image.
If this was the case, working with Object Styles in templates would be VERY much improved and reliable. So please vote for this improvement on the Tracker here!