Flamethrower is a stand-alone utility, but SystemImager maintains a SystemImager seperate copy (/etc/systemimager/flamethrower.conf) of the Flamethrower configuration file (/etc/flamethrower/flamethrower.conf). Each of these three commands (getimage, mvimage, cpimage) will create an appropriate entry in /etc/systemimager/flamethrower.conf for the image you specify.
It is also possible to manually add an entry, if you feel compelled to to so. Take a look at the flamethrower.conf man page, or the comments inside the configuration file (image entries go at the very bottom of the file). However, it's much easier to just do a:
"mvimage my_image-v1 tmp_name && mvimage tmp_name my_image-v1"