The Sizing tab contains properties that define how embedded or linked picture or OLE objects are sized when published into a Windows Help system. Sizing does not apply to video, coded RTF, or OLE object files.
File sizing method
Enables you to choose how a picture file will be sized in Windows Help, either by scale (percentage of original file size) or by size (in cm).
Help file scaling
Defines the height and width of the picture inserted into Windows Help as a percentage of the original file size.