I ve seen Edoktor has put in pretty much a good summary image flying bus swarm which IMO is perfect for describing the episode and meeting NFC requirements The second image of a close up of the alien may or may not be necessary it depends how well one feels the current infobox image does representing the aliens Given that if we say they are manta ray like and consider that in light of the info box pic I think it is duplicative However there may be good cause to illustrate the alien depending on what nfo there is in development