This paper explores the function of the visual syntax of images in Greek primary school textbooks. By using a model for the formal analysis of the visual material, which will allow us to disclose the mechanisms through which meanings are manifested, our aim is to investigate the discursive transition relating to the view of nature and the human-nature relationship between two series of natural science textbooks. The model is applied to a total of 635 pictures; 434 coming from the old series of textbooks introduced in the early 1980s and 201 from the new introduced in 2006. The results show that a) no differences in the codes of the visual representation of nature or human-nature relationship were recorded between the two series of textbooks, b) the environmental rhetoric mediated by the pictorial material of the textbooks appears closer to its lay counterpart than to scientific rhetoric, c) both series of textbooks favor a viewer-picture relation which diverges from the epistemological (subject/object) ideas of the romantic worldview and comes closer to the baroque one that depicts the world as non-linear and disconnected, while gives more freedom to the viewer to proceed to subjective interpretations. Thus, we assert that the baroque approach adopted by both series of textbooks does not aim at the initiation of students to the highly conventionalized ways of expression, and ultimately to the formalized and scientific rhetoric. On the contrary, within a constructionist context, the textbooks' visual mode allows students to equally share power with a quite familiar world.