Unfortunatly Family Echo does not have support for this option yet. It's in the FamilyScript spec but has yet to be implemented.
You can export a FamilyScript or GEDCOM file with all the data less the profile pictures. You can export an HTML file that will contain the profile pictures. If you ever need to restore a backup you can pull the picture data out of the HTML file into imdividual jpegs and manually enter them.
