I don't like the pictures. Sorry if this has been done before... I waited awhile because I thought it was just a "dislike of change" thing.
The models all look like....well....models, despite their stagy expressions. It's all thick curls artfully dishevelled.
The straw that broke the camel 's back for me was a post from a morbidly obese mumsnetter seeking support to lose weight. This generated a picture of a model who was clearly a size 14.
I think that if mumsnet really feels that it needs images something like cartoon drawings from a professional illustrator might be better.