goodroi - 12:01 am on Oct 13, 2010 (gmt 0)
google page speed is still in beta. in other words it is not perfect and is prone to reporting errors.
you could use google analytics (or any other analytics program) to track what visitors are coming from google images and if they result in a sale. the jewelry industry is more inclined to image search. dont forget there are many people who will search for butterfly necklace because they are looking to steal an image for a blog post or something similar.