1. A wearable computing device for displaying a graphical user interface, the wearable computing device comprising: a camera to generate a captured image; an image analysis module to analyze a plurality of prospective locations of the captured image at which a graphical element can be placed to generate image location metric data for each prospective location of the captured image, the image location metric data indicative of one or more image characteristics of the corresponding prospective location, wherein to analyze the captured image comprises to apply a filter to the captured image, wherein a window of the filter has the same size and shape as the graphical element; and a placement module to (i) determine appropriateness data for each prospective location based on the corresponding image location metric data, the appropriateness data indicative of a relative suitability of the corresponding location for display of the graphical element; (ii) select one of the prospective locations based on the appropriateness data; and (iii) display the graphical element on the graphical user interface at the selected prospective location.