Hi @KCC11,
Thanks for sharing your suggestion, and welcome to the Roku Community!
Currently, the feature to customize the picture speed and transition for the Roku photo stream is not available. As we eagerly anticipate the upcoming feature on our Roku Devices, you can continue to take advantage of the latest features offered by Roku Photo streams.
For more detailed information, visit this support FAQ: How to use Photo Streams on your Roku® streaming device.
If there's anything else that we can do to assist you, please let us know.
All the best,
John
John
Roku Community Moderator