A steady drizzle has painted the near-roseless Rose Garden gloomy gray, and President Carter's mood is even darker than that as he walks along the passageway beside it.

"Where did the Post get that story?" the president asks Gerald Rafshoon and Jody Powell, who are walking with him to a Thursday breakfast meeting with reporters. "It's not true, and it defeats our whole program."

The object of Carter's displeasure: The Washington Post's front-page story quoting "administration officials" as saying Carter may relax his 7 percent wage standard by exempting some fringe-benefits costs from that ceiling, to avoid a fight with the labor unions.

The problem as Carter sees it: A program based on voluntary compliance will not work if the administration is being depicted - by its own officials, no less - as being weak and vacillating on its own guidelines. And Carter is right.

"We're not going to back down on that program," Carter tells Rafshoon and Powell. "And that's what we've got to make clear."

Policy and image. It is at times like these that they come together. And it is at times like this that the offices of Gerald Rafshoon come into particular need.

Rafshoon is the man who directed the advertising and imagery in Carter's 1976 campaign and who officially signed onto the Carter senior staff last July. The title of his job is assistant to the president for communications. The public perception of his job is that he is some sort of Rasputin/Svengali in charge of restructuring the president's image.

Image . The mere mention of the word makes Rafshoon and his staff cringe; and for good reason, because that is not what his job is really about. In fact, you don't even have to mention the word image to get a good cringe out of Rafshoon. Just tell him you are doing a story about him. "I don't want any stories about me," he says. "Just don't write anything."

But if presidential image-maker is too strong a term for what Rafshoon seems to be doing, assistant for communications is just as misleading. Rafshoon is far more than that. He seems to be, in fact, a presidential chief-of-staff in all matters that involve Carter and the public.

Earlier this fall, domestic-policy chief Stuart Eizenstat recommended that Carter should announce personally the new proposal for $250 million in benefits for Vietnam-era veterans. According to two sources outside the Rafshoon shop, Rafshoon intervened. He argued that Carter should not get personally involved because it was a "no-win situation"; veterans groups would surely attack the program for falling short, he said, and there was no need for Carter himself to become the target for the veterans' criticism.

An intra-White House battle ensued. But Rafshoon held firm. And it was Vice President Mondale who was trotted out to make the announcement. (News accounts the next day coupled pictures of Mondale with the complaint from veterans that the program was "too little and too late.")

The mysterious role of Rafshoon becomes a lot less mysterious by understanding how he functioned in that wage and price snafu.

By mid-morning Nov. 16, Rafshoon deputy Greg Schneiders had spoken to officials from the Council of Economic Advisers and the Council of Wage and Price Stability. His message: (1) The story needs to be killed - we'll do it at the White House; (2) every official must get the word they can discuss the "nuts and bolts implementation" of the program, but only the president will be speaking about and making decisions on policy.

Scheiders, apparently not out on a Haldemanesque search-and-destroy mission, never asked who had put out the story; but he did ask each of them how such a story could have gotten out. And in the process he was given the name of the source, an economist at the Council of Wage and Price Stability who, he was told, had been trying to give a reporter an example of how the technical facets of the program might be implemented. It was stressed that the economist was a good and capable person who was trying to be helpful to both the administration and the reporter; and Schneiders concurred, and the source escaped White House wrath.

And that is interesting, because much later at least one of the president's most senior advisers remarked that he was sure the source must have been someone who was out to "wreck the program" because of his own political leanings and that the source must be ferreted out and dealt with strongly. That is the sort of evil-genius assumption that is made frequently - regardless of the administration - by those closest to power, and it is the sort of assumption that often is, as in this case, dead wrong.

Meanwhile, another Rafshoon aide was setting up a long-range program for public appearances by Carter's chief economic czar, Alfred Kahn - including themes Kahn should stress.

The arrival of Rafshoon has meant that many senior advisers are no longer getting their way as often as they would like. But this has not touched off an in-house revolt. Consider the view of Eizenstat and his staff losers in the veterans-announcement battle.

"Stu feels that Jerry has brought in a much need perspective," says one of Eizenstat's top aides. "And sometimes we may not be as sensitive to that side of it . . . Stuart feels his job is 10 times easier . . . I mean, it's much more enjoyable to play the game when your team is winning."

EPILOGUE: The Post story also carried another section that brought Carter no happiness. It was the second recent slip-up by Kahn - a quote from a speech in which he said if the anti-inflation effort fails, the nation will face "a deep, deep depression." The comment promptly knocked the climbing stock market into a deep, deep decline. Days earlier, Kahn had let himself get pressed beyond his original "no comment" in a television interview and wound up saying he would prefer mandatory wage-price controls, which Carter opposes, to a prolonged recession.)

"I'm going to have to help Kahn out," Rafshoon told another senior Carter adviser. "I have a lot of respect for him, and he'll be very good. But Kahn has just got to learn to tone it down - and that you just don't have to answer all the questions all of the time."