The larger words are searched for more often than the others on each image but the question is about the words most often searched for as it applies to all images. I think you would have to go through each image and note the largest words then make a list and then try to guess which of those many were the most searched for. A larger word on a piece of fruit is not the same as the largest word on a businessman using a laptop. Is banana searched for more often than businessman? Still a mystery.