Pictures only capture a brief moment of a public figure's life -- definitely not their 24/7 life, I have seen pictures with Katie Holmes smiling while shopping at MJ boutique on the exact same day.
Even if she shops alone does not make her an uncaring mom or lonely person (some ppl rather shop alone). My SILs leave the kids at home with my brothers when they do their grocery/christmas shoppings. I'm sure that there are countless mommies who do the same thing.