There are many examples of context effects in survey measurement. Responses to survey questions can be shaped by the order of questions, the format of response options, the broader survey environment, and so on. For Web surveys, the inclusion of visual images is a trivial design issue, but may have consequences for the responses obtained because they change the visual context. We report a series of experiments examining how responses may be affected by the use of images in Web surveys. Specifically, we examine the effect that pictures of a healthy woman exercising versus a sick woman in a hospital bed have on self-rated health. We replicated the experiments in three different surveys, varying such factors as the size and placement of the image and the location of the question within the questionnaire. In general, we find that when exposed to a picture of a fit woman, respondents consistently rate their own health lower than when exposed to a picture of a sick woman.