Which is exactly what organizers of the just wrapped "Australia from above" contest were likely aiming for when they launched the competition in March.

整个句子其实是个定语从句，修饰前一句的某个词或词组或整个句子。which是关系代词，在从句中主语。is是系词，exactly为状语，what至句末是表语从句。what等于the thing which,在表语从句中作were aiming for的宾语。organizers of the just wrapped "Australia from above" contest为表语从句的主语，when they launched the competition in March.为表语从句的时间状语。