There is a picture on the wall of the Icelandic players' team room in their quiet Alpine retreat in south-eastern France. It depicts a rhino fleeing a snappy little chihuahua dog.
Let's say the rhinoceros is England. And the hound is Iceland. And this is a little bit of the psychology which Lars Lagerback, the Swede who helps to coach Iceland, puts into the team that qualified for the Euros by beating the Netherlands home and away, and beat Austria and drew with Hungary and Portugal in the group stage of the European Championship.
Iceland (or Island to go by what is written on their shirts) are the underdogs that bite.
Tomorrow night in Nice, they meet England. And if anyone is afraid, it is not the Iceland chihuahuas.
Size, and salary, are not everything. Nor is reputation, though the Icelandic players to a man follow English football, or rather the multi-national Premier League on TV during the long, cold, dark winter months up near the Arctic Circle.
Rooney is still a workhorse, but having hit 30 years of age, he is willing to do his running in midfield, to sublimate personal glory for the good of the team.
Imagine this: A country way less than one-tenth of Singapore's manpower, squaring up to England in a straight knockout fight.
Put another way, Iceland's total population of 331,747 is equivalent to that of Leicester. And England knows what Leicester stands for in football right now.
"We are not the chihuahua!" Theodor Elmar Bjarnason chided the British media. "If you underestimate us, it's a mistake."
England won't do that. Their manager Roy Hodgson cut his teeth in coaching by working with Swedish teams, and also coached in Copenhagen. So he knows the Scandinavian mentality, and they know him.
They also know, how can they not, that Wayne Rooney has been around the England line-up since 2003. It would be rude to describe Rooney as a rhino, though in his youth he had the temper of a raging something-or-other.
Tomorrow's game against Iceland happens to be a landmark in the career of Rooney. It will be his 115th cap, which puts him level with David Beckham as the most-capped English outfield player of all time.
The list of top England appearances is led by Peter Shilton (a goalkeeper) with 125 appearances. Next come Beckham and Rooney. And after them Steven Gerrard (114), with the greats Bobby Moore (108), Bobby Charlton (106) and Billy Wright (105).
Rooney's feat, I would say, is better than Beckham's for the simple reason that Beckham in the last years of his career picked up caps for small-time substitute appearances. He was, and is, enhanced by his commercial factor.
But Rooney equals another man on 115 caps - Zlatan Ibrahimovic. The Great Zlatan last week called time on his national team career after failing to score or to win a game in this Euro.
Ibrahimovic said he wouldn't go out in a whimper. He did, because he just couldn't go on carrying the Swedes. Zlatan's total of 62 goals for his country, incidentally, is 10 more than Rooney currently has.
But you may have noticed there is a change of role, and almost a change in the personality, of Rooney. He is no longer the main attacking threat for England now that the manager can choose between Harry Kane, Daniel Sturridge, Jamie Vardy and Marcus Rashford (probably in that order tomorrow).
Nor is Rooney any longer the belligerent child he was in his pre-Manchester United days at Everton.
He is still a workhorse, but having hit 30 years of age, he is willing to do his running in midfield, to sublimate personal glory for the good of the team.
England need him there because they have had no creative passer in midfield since Paul Scholes retired.
That change in Rooney's role, for United as well as for England, has brought out a change in demeanour, even in speech, that we might perhaps never have envisioned.
He is the manager's assistant, on the field and in front of the media.
To hear Wayne Rooney talk now, with less of a Scouse accent that used to baffle the English never mind foreign audiences, is to listen to a measured man, with something to say.
Look at his eyes when he speaks, and you see a person more sure of himself and his place in the line-up. Clear eyes, unafraid and un-self-conscious.
"You don't play for the achievement of getting to a quarter-final," Rooney said at his most recent press conference.
"We want to win the competition. That's our aim, so I'm not going to sit here and say we'll be happy with the quarter-finals, the future's bright because we are a group of young players."
The tournament, he said, starts here.
Asked about his responsibility to this young group, he responded: "I don't want to be remembered as a captain who wasn't good for his team, wasn't good for his team mates, and wasn't good for his club or country."
That thoughtful approach almost sounded like he had been taking elocution lessons from manager Hodgson.
He was asked about the old Rooney, or rather the rash young Rooney who seemed forever on the verge of a red or yellow card for outbursts towards officials.
"When it didn't go well, it would build up inside me," he answered.
"I think I'm a different player to what I was then.
"I think I've matured a lot, I'm different as a player and a person. You learn from it."
And this maturity comes from?
"I think, first of all, it was having kids. It made me look at things differently."
Certainly it does. Few of us could be Wayne Rooney, the player. Many of us can say that we know how being a father changes us as people.
So Hodgson and England can thank Kai Rooney, age six, Klay Rooney, three, and Kit Rooney, born in January this year.
Those boys will grow up wealthy, as the sons of England's all-time record scorer, and now captain.
Their dad's temper is less likely to be let off the leash if the Icelanders push England to the brink tomorrow now that he carries responsibility for the team, the country, and the kids.