EC Giruno

The train service on the 'Gotthard route between Switzerland and Italy has been transformed in recent years, new infrastructure including the world's longest railway tunnel, has now been complimented by new trains.

So new that ShowMeTheJourmey has yet to travel by them, hence the lack of an insider guide and the images being some of only a handful on SMTJ that its writers haven't captured.
Hence this link to The information on the SBB website about travelling by these 'Giruno' trains.