Is this a natural grammar or some kind of joke/internet meme?
Cute girl is cute.
Poor child is poor.
Troll topic is troll.
This sentence structure is somewhat deficient because it is lacking a determiner (e.g. a or the) in the subject noun phrase which would normally be present. The repeated adjective is not ungrammatical since grammar does not describe semantic choices, but it is redundant and seemingly pointless.
Looks like it's a passing internet-generated fad.