The flag is recorded against the comment.
There is no action to be taken, because the comment has been deleted. However, you flagged it as unfriendly and that is recorded; the system does notify moderators of a clutch of unfriendly flags, once a threshold has been reached.
I'll reiterate @ColleenV's comment, since it's worded well and fits in the answer:
Sorry for causing confusion.
The appropriate flag for content that is just nonsense is "rude or abusive" because posting nonsense is rude (deliberately unhelpful).
Flagging it as "rude or abusive" also helps get it deleted automatically, the same as a spam flag.
If you are unsure if someone is either deliberately posting nonsense or ...
The migration option is under A community-specific reason:
Clicking on 'This question belongs on another site ...' reveals another problem: Philosophy isn't listed in the so-called migration paths:
Only ♦ moderators can migrate questions to arbitrary sites in the network, so you'll have to raise a custom flag, as indicated in the FAQ about migration.