How can Google do this? By hosting the pictures on its secure servers first, Google takes the risk out of automatically loading pictures on your Gmail messages. The updated version of Gmail should soon be waiting for you at the Google Play Store under My apps. If it's not there now, it should be there soon, so keep checking.
By the way, in case you were wondering, the screenshot on the left shows that you can change the settings so that images will still require your permission before appearing. If you disable the new images support, you will be asked once again to tap on the link to show pictures.