During the episode, Clive shows pictures of the Doctor by himself in various places (Krakatoa, JFK's assassination and at Southampton when the Titanic set sail). However, during this episode the Doctor implies several times that he has recently regenerated. You would expect the pictures can't be from the Doctor's future, because Rose is always with him until he regenerates and she's not in any of the pictures. But if he just regenerated before this episode then he couldn't have visited them in his past, either.
There are however acknowledged gaps between on screen episodes. In Boom Town Rose tells Mickey about places she has visited with The Doctor that are not shown on screen in previous episodes. So Rose could be travelling with The Doctor in all the instances found by Clive, since there is no guarantee she is standing right next to him at all these locations, so would not necessarily appear on the photos.
Plus, The Doctor could have travelled to these places in between the time when he leaves Rose and Mickey at the end of episode one, to when he returns saying "did I mention, it also travels in time?".