literally, this sentence means ‘one plus one is 귀요미’.
this sentence is a part of 귀요미송(귀요미song)’s lyrics.
This sentence sounds like some childish and cute.
In Korea, adorable grown-up women are supposed to have 애교(aekyo; means ‘some pureness and cuteness like a baby has’). This sentence is a kind of tool that shows 애교.
it’s not important what this sentence has literal meaning. The fact that this sentence is a tool of 애교 is important.