HTML Export exports images embedded in notes. Note that the images are exported into the same directory as the note's HTML file. Prior to v6, notes were exported to a subdirectory of the note's folder. The exported images are JPG, and take the host page's name. If note 'About' has 2 images, export with create 'About.html' alongside 'About.jpg' and 'About1.jpg'. Note the image numbering is essentially zero-based but the zero is not applied, i.e. if a note only has one image, as it most likely, the image will have/need to number.
The number of images embedded in a note is stored in $ImageCount. Any note with an $ImageCount of more than zero will have images embedded in its $Text.
If previewing HTML pages and the document has not been exported, i.e. no export folder is set, and images needed for preview purposes will be generated and placed in the same folder as the TBX. Therefore It is a good idea to set an export folder, at minimum before using HTML preview if using inline images.
Text images are not exported via text export.
Picture adornments are not exportable (but are included if copying an image of the whole map).