Maybe you have to read between the lines, but here are the facts. Baz Luhrmann's Australia is a very big picture – not much short of three hours, epic landscapes, a lot of special effects, Nicole Kidman and Hugh Jackman, and a final budget at around $130m (£87.5m). Reports from the US suggest that it grossed less than $20m (£13.4m) in its first week. On December 4, the New York Times ran a full-page ad for the film. It quoted chunks from the many friendly reviews. But the image was not Kidman and Jackman in a torrid embrace, not Japanese planes attacking Darwin, not 1,500 cattle on the enormous plains. No, it was a winsome close-up of Brandon Walters who plays the mixed-race boy in the story and who does so much to make the movie work. The marketing of Australia has shifted in 10 days: now, it's a picture about the kid.

All of which tends to sustain one of the more remarkable trends in recent movie history: the way in which Nicole Kidman has become hard to sell. Australia looks set to join a list of Kidman films with a US gross considerably lower than what it cost:

The Golden Compass

cost $180m (£120.9m), grossed $70m (£47m)

Margot at the Wedding

cost $10m (£6.7m), grossed $2m (£1.3m)

The Invasion

cost $80m (£53.7m), grossed $15m (£10.1m)

Fur

cost $16m (£10.7m), grossed $220,000 (£147,740)

Bewitched

cost $85m (£57.1m), grossed $62m (£41.6m)

The Interpreter

cost $80m (£53.7m), grossed $72m (£48.4m)

Birth

cost $20m (£13.4m), grossed $5m (£3.4m)

The Stepford Wives

cost $90m (£60.4m), grossed $59m (£39.6m)

The last Kidman picture that approached "hit" status was Cold Mountain, which cost $83m (£55.7m) and grossed $95m (£63.7m). And Cold Mountain was generally regarded as a failure in the year it opened, particularly in the Academy awards. I'm not saying that every one of the films listed above ended up losing money, particularly if you factored in worldwide box office and video revenue. Nor do deplore every title: Birth and Fur seem to me audacious adventures for anyone – and Birth, I think, is one of the most seriously neglected films of the last 10 years. Kidman has always tended to be at her best in difficult rather than mainstream roles. I would say that The Interpreter, Bewitched, The Invasion and The Stepford Wives were unworthy of her, while Margot at the Wedding is a small gem.

A lot of this indicates the peril of being a brave, independent actress beyond the age of 40. And the bigger the picture, the greater the peril. This is the third time Kidman and Luhrmann have worked together. Before Australia they did Moulin Rouge (some hated it, some loved it – I'm in the latter group) and ... can you guess ... yes, the notorious Chanel No 5 commercial which at a per minute cost was probably the most expensive film Kidman has ever made.

Nicole Kidman, Hugh Jackman and Baz Luhrmann at the UK premiere of Australia guardian.co.uk

In the Chanel ad (as in Moulin Rouge) she is absurdly beautiful – and magically dressed. In Australia, give or take a few cocktail dresses from London, she wears what Australian women in the Northern Territory would have worn in 1940. Not a high point in the history of fashion or glamour, and Kidman, I think, sometimes feels more at ease if she looks sensational. This is an actress who needs to be put in chic clothes in romantic comedies where she can be funny, and wicked, and drop a few of the clothes. Otherwise, it's the kid's picture.