Sex, for better or worse (usually worse), is objectifying. I remember reading that and feeling offended by the sentiment, but I've come to realise that it's quite true. Sex is a physical pursuit and it is not intellectual stimulus that you are seeking. You can be attracted to someone's mind - pretty much what relationships should be based on - but for sex itself the mind is not an overly important feature. More of a hindrance, if anything.
I've just then come to the conclusion that this is probably because we were having sex before we'd invented higher reasoning. The two simply aren't connected, at least at a conscious level.
Back to the ad, I think the real issue here is that "objectifying" and "misogynist" are considered to be synonymous. Jane Caro again picked up on this, pointing out that this ad was clearly a fantasy and that almost everyone would see it as such. Sexy women being sexually attractive do not hurt the cause of feminism; they're simply a fact of life and frankly they make it rather pleasant. What is truly insidious in the media is the portrayal of women's minds, or at least their behaviour.
Take porn magazines, for example (I've only ever read Anna's - I went from zero to internet porn pretty much instantaneously). Pictures of boobies and vulvas (although vaginas get a good look-in too. These things are pretty much gynaecological periodicals) by themselves are not misogynist or unfeminist. However, the text that surrounds the picture is a grotesque mockery of male/female interaction and it is this that is so damaging to gender equality.
A hot naked chick by herself is only going to leave the "reader" sexually satisfied, whereas a paragraph on how manly it is to fuck all the chicks you can as roughly as possible with no considersation to their physical/emotional wellbeing, with a supposed woman affirming this, is going to massively shape someone's understanding of gender relations. Even a well-adjusted adult would find it hard to resist being lured into the magazine's persuasive (read: macho) tone, and female agreement renders the damage almost irreversible.
This is probably the main reason I love the film clip for "Destination Calabria" (apart from the fact that it's AWESOME). Other film clips, particularly rap videos, depict gender relations and they are almost invariably misogynist, depicting women as entirely under the thumb of men. Moreover, the more women a man has the more man he is. However, Destination Calabria doesn't do that. It just so unashamedly shows sexy women being sexy and it doesn't make me feel like subjugating women at all.. it makes me feel really good and just that little bit more appreciative to the whole female gender.
So there's the problem, in summary. It is not the sexual objectification of women that is damaging, but the affirmation that there is nothing more to a woman than sexual objectification. This extends to nearly every portrayal of gender in the media - it's not the portrayal itself but the implication that there is nothing more to that gender.