This is wrong. Just look at this page: http://uk.ign.com/wikis/xbox-one/PS4_vs._Xbox_One_Native_Resolutions_and_Framerates
Assassin's Creed, Battlefield and Ghosts are the three big cross platform releases at launch and are all graphically inferior on the one. Wont go into the technical details, but will say that the PS4 is capable of running games in greater detail, be that frame rate, resolution, AA...
Nothing is certain, but most guess that cross platform graphics disparities wont increase over the life-cycle. So FIFA, CoD etc. will always look better on the PS4, but the gap wont grow too much. However, you will see significant disparities between the two consoles on their in-house exclusives.
So, PS4 is and will remain the graphically superior console of this generation, but the differences in quality may very well be negligible for cross platform releases.
You can play guess the console with these gifs of the graphically uninspiring Ghosts: