The shot and its source
In the image, Robert Downey Jr. stands in a dark striped suit and sunglasses, arms spread wide. Behind him are snow-capped mountain ranges, dry rocky ground, and dust kicked up on the right side of the frame. This kind of staged landscape is typical of promotional and film photo shoots, and the composition works as an image of a confident hero.
We did not come across the original photo set or the exact shooting date in open sources. The dating to 2008 is tied to the release of the first "Iron Man" film, but this is a supposition rather than a confirmed fact: we were unable to verify the original source.
Two versions
The meme is used in two versions that differ by the shots they draw on. The first relates to the first "Iron Man" film from 2008, where Tony Stark first appeared as a billionaire inventor. The second relates to the second film, from 2010, in which the hero finds himself at the center of a political and personal conflict and continues to display his signature bravado.
Both versions work on the same idea: the hero displays absolute self-confidence even when there's no particular reason for it. That's why the caption is often adapted to a specific situation, while retaining the overall sense of self-irony.
How the caption came about
The phrase "Robert Downey is cool" and "Tony Stark is cool" arose as a joke about the actor's charisma. Tony Stark is known in the films for his wit, self-confidence, and habit of talking about himself with irony, and viewers often perceived the role as an extension of Downey's own personal charm.
It was not possible to establish the exact author of the caption or its first use. It most likely took shape in fan discussions on forums and social networks, but we found no direct confirmation of this, so the phrase's origin remains unestablished.
How it's used
The picture is most often used as ironic "bragging" or a reaction to a successful feat. For example, when a person has handled a difficult task and jokingly shows off their win, the caption "Tony Stark is cool" fits perfectly. It's also used when someone does something impressive in front of friends.
There's also the opposite use: the picture is posted in response to someone else's self-praise, to poke fun at excessive confidence. This usage depends on context, and within one and the same discussion the picture can read as either support or mockery.
Cultural context
The meme shows how a character's image becomes part of the language of the internet. Viewers associate the spread arms and pose with the franchise's films, but in memes this association turns into a universal gesture of "I'm fine, everything's under control."
Like other memes featuring actors, this picture relies on a public role and a fictional image rather than on the personal traits or appearance of a real person. For that reason it's considered harmless, though, like any meme, it can be put to different uses, and its meaning is determined by context.