One For The Engineers

Went 'round to look at the Myford last night, turns out to be an ML10, comes complete with all sorts 'o attachments and good stuff.
Amongst the rest of the stuff in there, is this. Now I never dreamed that a miniature shaper would ever exist, but here one is. About the size of a big shoe box it's 'kin amazing, can't see the little lady letting me put it on the mantelpiece though.
You don't see many shapers about nowadays let alone miniature ones, so this was a shock, but what I can't figure out is this; what would be done on a shaper that a mill can't do ?