It is not possible to just get the checksum without fetching image, we dont support fetching just image checksum. Image checksum for buddy's image is always sent through buddyInfo. If the image of userid has changed after the Get, then buddyInfo will have the checksum on new image. There are no other cases where image checksum will be different in buddyInfo and Get response.
Thank you :)Why is the checksum when I received a notification of buddyInfo different than the checksum when I do a get method to "http://displayimage.messenger.yahooapis.com/v1/displayImage/custom/yahoo/" +id ?