How did you determine, from looking at an artist’s rendering of a feathered dinosaur, that the artist intended to convey to you that this drawing was a accurate representation of what that animal looked like, right down to the placement and color of each feather, and not simply a illustration of what one might have looked like?
An artist's imaginative rendering, imaginative since what dinosaurs looked like in detail is unknown, is an attempt to give visual imagery to what is purely speculative. If the writer says this is just what is the possible appearance of a feathered dinosaur, the artist has provided something concrete and in lifelike detail.
The question of actual vs. possible is of far less importance than the detailed drawing that conveys the message that not only is this possible but here it is.
And I would further suggest that the illustrations of what something looks like that accompany text have a far greater impact on what the viewer thinks the text is saying than the words of the text its self.
I don't think the sharp distinction in your question exists when talking about how something looked physically.