A textual feature is any "physical" clue, like bolded words or highlighted sidebars, which emphasizes information. Go to a website of your choosing and ask yourself the following questions: What types of textual features does the site use to emphasize information?
Does it use bulleted lists?
Are there any bolded headings?
Does the text contain highlighted words?
Are there pictures/graphics?

Read the following passage: he roamed from chamber to chamber with hurried, unequal, and objectless step. the pallor of his countenance had assumed, if possible, a more ghastly hue— but the luminousness of his eye had utterly gone out. the once occasional huskiness of his tone was heard no more; and a tremulous quaver, as if of extreme terror, habitually characterized his utterance. there were times, indeed, when i thought his unceasingly agitated mind was laboring with some oppressive secret, to divulge which he struggled for the necessary courage. which of the above ideas might be considered foreshadowing? he is wandering all over the chamber his skin tone is really pale his voice is quivering the narrator thinks he is laboring with an oppressive secret