So I was rewatching Cabin Fever yesterday, and maybe I found out why did that mysterious eye (probably mib) appeared to Hugo - so mib could scare him. Why?. Because MIB wanted John to go in cabin alone so he could tell him to move the island. As seen in Cabin Fever, neither Ben or Hugo wanted to go inside. He knew that now that Hurley knows where the cabin is, that he will tell it to John so John will take him to help him find the cabin. Thats why mib said 'help me' in 'The man behind the curtain', so it would make Ben jealous and realise that his time is over, so he wouldnt want to enter the cabin and speak with "Jacob".