Google said there will be a new “source” line item for image search reflected in Google Analytics which will display as “google images” in the Source report and “google images/organic” in the Source/Medium report within Analytics. Here is a screen shot of how it will look:
Google said the images.google.com line will still show in the Referral report, as before. But when this change happens, the “google/organic” line under Source/Medium will not include Google Image search traffic. Instead, that will be segmented into just the “google images/organic” line.
Google said that some users may notice a drop in traffic, “perceived to be coming from ‘google,’ since it will be reclassified as coming from ‘google images.’” But Google added, “[I]n some cases, you may see an increase in organic traffic as we reclassify some traffic previously classified as ‘referral’ to ‘organic.’ These changes should all balance out, and you shouldn’t expect an overall drop or increase in total traffic.”
If you set up special filters, you may need to reclassify those filters when this change rolls out. Google said, “[Y]ou will want to make updates as needed to capture the new Source parameter in your custom settings.”