fix(review report): return readable image list in csv

And unless we know if the (native) compiler hoists it (by say loop unrolling) outside the loop after it is _sure_ that i > 0 so the runtime overhead does not occur, we can't say for sure (I am not saying this is not possible, just that we need to be sure). Plus you are allocating another array imageSrc just for this purpose. Is that needed? IMO, join is better if somehow image.toString (or whatever) can be called along with appending of the separator.