Shaky Icons

How would you optimize the images?

Optimize real image size in pixels , there is no reason they should be bigger than they display. Then optimize Q Factor (Quality). Use some good picture editing tool . Google Picasa is free and it makes very good images. If you have something like Adobe Photoshop that would be even better.

I did what you suggested - but no noticeable difference.
Can you take a look at it, please?

Can you try with refresh interval 20 or even 15 ?

I set it to 15. The problem I see is the Rotation Speed in relation to the fps value. If the fps is increased and the rotation speed is fast, then the image spin is fairly smooth. But when I slow down the rotation speed, that's when the images become more shaky. I need a slower rotation speed so users can have a chance to read the text.

Based on the above, is there any way to account for the shaky images at a slower rotation speed in relation to the fps value?

You have parameter in module configuration for that "Rotation Speed"