The purpose of this article is to explore the relationships between text and illustration in brand-image advertising for Texaco. The four advertisements studied were published in 1999 issues of a popular American science magazine, 'Discover'. Two of them are based on a metaphor, and the picture illustrates the text metonymically in the other two. In a questionnaire completed by 91 students from the U. of Grenoble (France), only a minority (even among geologists) could guess the subject of the advertisements by looking at the pictures alone. This seems to be a deliberate rhetorical strategy: the reader's attention is caught by puzzling pictures that have only tenuous metonymic or metaphoric links with the text, so we are tempted to read the advertising copy in order to make sense of these pictures and do so without knowing from the start who the target audience is. This Trojan horse tactic catches us in a state of "willing suspension of disbelief," and increases Texaco's chances of proving how good they are at protecting the environment. (LLBA 2001, vol. 35, n. 4)