I suppose if you are not familiar with visual industry, it might be really difficult to figure out whom to contact in the first place.
And even real products that would benefit from actual visual design might just "hack the visuals" together. So this is not that far out.
They do discuss hiring external resources if you read the article -
"If we had known precisely the globe we wanted to build, we’d have been foolish not to hire GlobeKit. Instead, not knowing what we did not know, we decided to figure it out ourselves. "
And they do have internal designers on the task as well-
"To start, the project’s design lead created the best approximation of her vision of the globe in Photoshop."
And even real products that would benefit from actual visual design might just "hack the visuals" together. So this is not that far out.
They do discuss hiring external resources if you read the article -
"If we had known precisely the globe we wanted to build, we’d have been foolish not to hire GlobeKit. Instead, not knowing what we did not know, we decided to figure it out ourselves. "
And they do have internal designers on the task as well-
"To start, the project’s design lead created the best approximation of her vision of the globe in Photoshop."