Reduplication of Adverb + Adjective in 很细很细
Wayne Cheah wrote :


  What is the purpose of "很细很细" -- same as "very, very small..."


And that should be the answer. I would give more examples to support it

很细的针 a very small needle 

很细很细的针 a very very small needle / a small small needle

很遠的地方 a far away place/ a place far away

很遠很遠的地方 a very very far away place/ a place far far away  

很大的手 Very large hand (a big one)

很大很大的手 very very large hand (a huge one)