"We need to look at everything, as we develop the next game," said Robert Brent, the chief financial officer of Eidos. "Look at how Batman changed succesfully, from the rather sad character of the Michael Keaton era to the noir style of The Dark Knight."
Eidos typically expects Tomb Raider sales to be split half-and-half between Europe and America but the American sales were considerably lower than anticipated. The image revamp is primarily intended to make Lara more appealing in America again. We'll have to wait and see what they do with the series and Lara herself.