Having a dead loved one (or close friend) come back one last time so you could say goodbye to them properly and receive closure seems to be a common theme in Joss's works. Buffy saw her mother in 'Normal Again'; so did Spike in 'Lies My Parents Told Me'; Wesley saw Fred in 'Not Fade Away'. Now, thanks to Dollhouse imprinting technology, Adelle has done it too. I do think we're supposed to see imprinting as a double-edged sword that can benefit people, rather than a wholly evil mind-control weapon.