To dream of only shapes may reflect empty logical thinking. Possibly a sign that you are too focused on using something for personal benefit without caring about the subtleties or deeper aspects of it. A lack of sensitivity towards something you only want to use. A straight forward mindset or result oriented attitude. A mindset that is avoiding emotional risk at all costs.
People who take ayahausaca commonly have visions that are specifically about geometrical shapes. This may reflect their logical and unemotional mindset about wanting to use the ayahausca experience for personal gain without wanting to participate in any self-reflection or personal improvement. It may also reflect their tendency to avoid the emotional risk of having to deal with their honest emotions which the ayahausca often encourages.
Refer to the themes section for shapes for a more in depth look at shape symbolism.