使用返回的JSON值设置NSString

I'm trying to set my imageView with the url returned in the JSON data below in "value" (secondLink). When I use the following code, it returns the entire block in JSON through my XCode console - what should my code look like if I ONLY want the image's URL to be returned (right now, I assume it's trying to set the imageView with EVERYTHING returned in secondLink)? I'm trying to set my imageView with the url ret