i would agree with the others amnd say its too bare. try adding some live/fake plants and some bogwood. maybe a cove or something aswell. i would also add a background. i do like the plant you have in now, its very good for a fake plant. not sure about the root structure thing, but thats my opinion.
i see a heater in there, so its a tropical tank, and goldifhs arent tropical, i would advise you take them back to the store. maybe purchase some more tropical fish, many tetras would be good. or livebearers (if you can deal with the fry), some small gouramies, or many others. i would suggest doing some research beofre buying anything, so money is saved and you get what you really want.
what size is the tank, did you cycle it?