Automatically, but in a way that, for some reason (typically because it is too complicated, or too ugly, or perhaps even too trivial), the speaker doesn't feel like explaining to you.
This term is quite old, going back at least to the mid-70s in
jargon and probably much earlier. The word `automagic' occurred in advertising (for a shirt-ironing
gadget) as far back as the late
1940s.