hmmm...there are some really long metaphors called parables, and those in it of itself are poems....just saying...so metaphors can be considered poems to an extent, meh this could be one of those really short one sentence poems
Poetry is art with words. He's as much entitled to calling it poetry as a lot of the avant-garde can call their stuff poetry. Whether it is good poetry is up to debate, but it seems fine to me.
