Not an expert here by any means, but from the images it looks like the chain might be a tad long. It might be perspective, but the chain looks a bit droopy. Like Bill said, does the new chain length match the old length?
The rear derailleur should have a little tension on the internal spring. By this I mean that the idler arm is pulled forward - at least a little - against spring tension when the chain is on the two smallest sprockets, front and rear.