As I recall , that picture was taken as Newt decided to join with Nancy to push global warming. He was trying to make a statement that global warming was not a political issue, and that he wanted a show of unity with a key Democrat that we needed to fight global warming.
Pretty much correct, except it looks a lot more like he was trying to get back ‘in’ with the people in power - witness how he’s regretted/not regretted that ad, he’s gone back and forth several times.
See post 14 about for original sources and the TV ad.