Embedding images in texts
First, you need to have uploaded some pictures to the Flux CMS. This is described in detail here.
Open a resource with the Bitflux Editor and point the cursor to where you want to insert the image. Click on the Insert Image icon of the toolbar. The image drawer appears from which you can browse through your files directory. After selecting the desired image, it will get inserted promptly.
Scaling images
Still in the Bitflux Editor, right-click on the designated image and select Edit Attributes from the opened context menu. Adjust the href attribute by prepending /dynimages/filesize (i.e. /dynimages/320/ ) to the path. The filesize indicates the new width (in case of a landscape image) or height (in case of a portrait).
The list of allowed sizes for scaling is defined in the main configuration.
There are more options available depending on the installation and version of your Flux CMS. For instance would /dynimages/160,0,gray/files/example.png not only resize example.png to 160px but also convert it to a grayscale picture.