Almost 25 years after the death of Marshall McLuhan, the Canadian writer who coined the term “global village” and philosophized about the impact that television had on our minds and bodies, some of his theories are taking on a larger meaning.

His most enduring idea was the concept of “hot” and “cool” media.

A hot medium is one that is “low in participation,” while the cool one is high in participation, “or completion by the audience.” Therefore the radio is a hot medium and the telephone is a cool one. The movies are hot, TV cool. McLuhan published this theory in 1964, and in the years since then the media have become so pervasive and interconnected that the idea of “participation” would seem to require redefinition. Broadcast TV may have been “cool” in the 1960s, but compared to cable TV and the Internet, it seems hotter than hell.

Even content has taken on aspects of hot and cool. Appreciation of so much programming is based on one’s understanding of the subtext, especially Japanese talk-variety shows, where the appeal of celebrities has less to do with their skills or comments than with the images they drag around with them. Their success as showbiz personalities is based on how successfully the audience has internalized those images.

This is why celebrities are so prominent in Japanese advertising. Endorsement isn’t the point, and neither is identification. The celebrity’s image itself lends relevance to the ad, but this relevance is often more complex than it seems. The current TV spot for Merit shampoo uses celebrity couple Isako Washio and Toru Nakamura and a young child that is presented as theirs. The words “mother” and “father” appear on the screen over this smiling “family” who all use the same shampoo.

The happy family image is strong because everyone who watches TV knows that the two actors are really married; in fact, their image is fortified by the understanding that Washio, a proper young lady, has softened Nakamura, whose original image was that of a tough young hooligan. She turned him into a loving husband and attentive father.

But it doesn’t stop there. Before Washio and Nakamura, the Merit campaign featured another young celebrity couple, thespians Saki Takaoka and Naoki Hosaka, who recently got divorced. When a celebrity signs up to do a long-term ad campaign, one of the terms of the contract is that he or she maintain a certain public image — otherwise the company can void the contract. Takaoka and Hosaka, who were considered a very attractive couple, had been doing Merit for a number of years, during which the tabloids said their marriage was on the rocks but that they were staying together for the sake of their advertising deals (there was more than one). Once the contracts expired, they divorced. So part of the impact of the new Washio-Nakamura campaign is that they’re not Takaoka and Hosaka.

Sony’s new Handicam campaign has a more practical subtext. It features Korean actor Bae Yong-joon, who’s a bigger star in Japan right now than he is in his home country. Sony normally eschews celebrities in its ads, since the prestige of the Sony brand is considered superior to any mere celebrity image.

Bae’s participation, however, has less to do with his star power than with his nationality. Over the summer, some of Japan’s leading electronics companies formed an alliance so that they could produce large liquid-crystal display panels more cheaply to meet worldwide demand, which is very high right now. Hitachi, Matshushita and Toshiba joined in, but Sony did not. Instead, Sony entered into a joint venture with the Korean company Samsung, which produces more LCD panels than any other manufacturer in the world. Bae’s appearance in the ad signals Sony’s solidarity with its new partner.

But sometimes the subtext is acknowledged and out in the open. The new All Nippon Airways ad campaign for its service to China features TV tarento and former pro-baseball player Kazushige Nagashima hitting fly balls out of a Japanese baseball field into the mitts of people in China.

Nagashima has his own celebrity cachet, but he isn’t using it. The main point of the ad is that he is replacing his father, baseball legend Shigeo Nagashima, who suffered a stroke last spring and is still incapacitated. Nagashima Sr. was in the original ANA ad campaign, which was an obvious response to the vast and expensive Japan Airlines campaign featuring Yankees slugger Hideki Matsui. In that ad, Shigeo was shown traveling around China on foot or by car, expressing his famous naive wonder at the sights (“That looks like a UFO”) and interacting with the locals, many of whom looked suspiciously like him.

Beyond Mr. Baseball’s participation, there was nothing really notable about the commercial. In fact, his son’s spot is much better — more imaginative, more visually striking. Every time Kazushige hits a ball, it is caught by a Chinese person set against a beautiful background who then says “Please come” in Chinese. Even a panda, lying on his back and munching on some bamboo, manages to snag a fly. According to the ANA home page, Kazushige says he’s just “pinch-hitting” for his father, which seems to imply that once Shigeo is well enough he will resume his place in the campaign. That would be a mistake. Compared to the old man’s spot, Kasushige’s is much cooler, and not just in the McLuhanesque sense.