The first thing that leaps out is that he's another left footed striker. Now we already have RVP and Lukas Podolski, so the attack is heavily weighted on that foot and on that flank.
We've seen RVP lose precious seconds and opportunities instinctually switch the ball to his stronger left foot. He's good at it but with inches to operate and a fast reacting defense closing him down, there have been numerous times when one wishes RVP had a stronger right foot. Scoring 30 goals is testimony to his incredible ball skills.
In the Euros, Poldi in his Portugal match came up against Joao Pereira who forced him to go inside and take shots with his weaker right foot. So far, he's been ineffective compared to how he usually fares in these big competitions.
Giroud also has that same strong instinct when we see the video clip but on balance he appears to be more comfortable with his right foot when forced as compared to RVP. He's also pacier, has an unmistakable aerial presence, and shows signs of developing back to goal skills, which are in line with a true centreforward. Wenger would be advised to make him more two footed which would be a desirable attribute since Giroud scores so many close to goal. The good thing is that he appears to be open to developing his arsenal.
This Arsenal side also has Thomas Vermaelen with probably the most wicked left foot in the Premier League. Does that make for predictability? Not necessarily so, because a very good midfield can find space and create service that allows RVP or Giroud to maximize scoring with their stronger foot. A lot of Giroud's chances at Montpellier were created by Younes Belhanda after Rene Girard switched him from the wings to a more central attacking midfielder position. Arsenal had some degree of success with Song to RVP and later on Walcott to RVP to keep the scoreboard ticking. Once Arsenal get back Jack Wilshere, the midfield should not be that spotty, with more settled service coming to the front.