I posted this icon today in takenote_icons and have gotten a few questions about using the "tween" function in Adobe Imageready before as well (notably for my Evenstar icon), so I thought that I'd write a tutorial on how to do this effect.
1. Make your base icon. It can be as complex or a simple as you want, but select a layer that you want animated, in our case, it's the Japanese text layer.
2. Duplicate the layer in Photoshop.
3. Use the "Motion Blur" function in the filters section, and set it at about 15-20.
4. Duplicate the layer again, this time setting "Motion Blur" at about 35-40, whatever you think looks best.
5. Duplicate the original, non-blurred layer one more time, and move it on top of the two blurred layers.
6. Export the file to Imageready.
7. On the first frame of animation, you should have ONLY the original, non-blurred layer turned on.
8. Make a new frame of animation, turn off the original layer, and turn on the first blurred layer.
9. Tween the layer for three new frames to the "previous layer" setting.
10. Do the same thing for the second blurred layer.
11. Set all the layer time delays to at least .2 seconds. To do this, there should be a small arrow at the bottom of the animation frames. Click on that to choose a time delay. You can make them fade as slow or as fast as you want by doing this. For example, in this icon, I set everything with a longer delay:
12. Use the "preview in browser" mode to check the delay speed, and make changes to your liking.
13. Save your icon as "optimised," and post it for the world to see!
Let me know if there's anything horribly unclear. I've never written a tutorial before! Visit my icon community, red_tavern for more cool icons.