The element that should be included in a summary of a text is the central ideas. A summary provides a concise overview of the main points or central ideas of a text. It aims to capture the most important information and convey it in a condensed form. While interesting metaphors and other texts on the same topic may be present in the original text, a summary should primarily focus on highlighting the key concepts and main message. Additionally, the reader's conclusions may vary and are not typically included in a summary as it aims to provide an objective overview of the text's content.