In medieval Europe, what we’d call a picture’s background was called ‘the throne’.
In this post, I might be attempting the impossible, but I’ll try to explain why the rumour is wrong which says that to read the Voynich drawings takes only ‘two eyes and commonsense’.
I won’t use jargon such as sign, signifier and signified because in my experience the more jargon is used, the less inclined are people to believe art-commentary is down-to-earth.
Instead, I’ll ask you – How many of these items are sunflowers?

Answer – NONE is a sunflower.
They are nine images – lines arranged in various ways, all of which were intended to trigger memory, among the intended audience, of matters already learned.
In each of those 9 images, the lines are arranged in accordance with a set of formal conventions. You have to understand those conventions if the image is to be intelligible, whether formed of the written- or the drawn line.
Anyone who claims they can read all nine images with ease must explain how they came by that knowledge, and address the big question of the disjunction between form and intended meaning, since we’ve agreed that none of the nine is a sunflower in fact, and none is formed in a way very closely similar to the form of any other.