France is a very conservative market. Funnily enough it's also quite vulnerable. I guess mouth-to-ear models have a lower impact there than they have in let's say the USA or the UK, and to get visibility in France one needs to make a name for himself before people start giving it attention. Our product is good, it can always be improved, the background can be changed of course, but the reason Mint isn't getting popular in France IMHO is simply because it hasn't made it to the French media yet.
Don't get me wrong I love the French market and I have a lot of respect for French consumerism (we French people have a unique way of making our market dynamic, bringing our prices down and always demanding better quality... if only that could happen here in Ireland, I'd be happier everyday).. but we also tend to ignore newcomers and favor established brands. Mint is relatively new and it's still being ignored in France. It will take time or marketing/PR efforts on our side for this to change.
PS: I made a study on the Linux related press in France last year and found out it was led by just few companies (minority of which were actually French). So far we've been very passive in promoting Mint and almost all promotion was done by the community itself. I guess sometime in the future we'll need to get in contact with the American and Polish agencies which are in control of the French kiosks. Anyway, bottom line is: It's got nothing to do with the artwork, and changing the background image isn't going to change anything here.