This is a “last resort” way to convert graphics, using Microsoft Word filters.
If a graphic imported into or exported from your FrameMaker document is neither WMF or BMP, and you have not mapped that graphic to another that is WMF or BMP, Mif2Go inserts an INCLUDEPICTURE field (Word 8) or IMPORT field (Word 7) in the RTF output to give Word a crack at the graphic. That is, Mif2Go puts the name of any graphic that it cannot process into an INCLUDEPICTURE (or IMPORT) field in the Word RTF file. If the graphic is in a format Word accepts, Word runs its own filter to import the graphic, creating an internal WMF in the process. The internal WMF is what you see as the graphic rendition in Word.