Well simply being able to understand an advertisement at first glance or first view might be good in that you understand it straight away, but the downside is that you do not give the ad enough time and thought.

With these X3 ads, BMW purposely does not include an image of the vehicle itself, nor does it includes images of snowboarding, surfing, off-roading and so on because it is 'too easy' to understand the message. By making the reader/viewer look at it more than once, it forces that person to think about what the message/s of the ad is, and hence generates mental stimulation.

Some may say that because the ad is 'complex' the reader will give up on it.. but this is human's we're talking about. Curiosity overides the minds desire to ignore the ad, so the reader gives the advertisement added attention.
And once the reader 'solves' or decyphers the meaning of the ad, he/she feels a sense of 'achievement' (happiness) which is then linked to the BMW brand. Ofcourse this may only be a minor link, but it all adds up ad after ad after ad.

And ofcourse, the fact that BMW use such 'mentally activating' ads as opposed to the status quo or a picture of a car and driver conveys to the reader that BMW does not stick to conventional means. In other words, they are different, they are innovative... and very creative.

Clever ads. Thanks Just Me for the post, and thanks to Eni for the explainations.