Because you've got music and movies streaming to your Apple TV, I know you've authorized Home Sharing under the file menu of iTunes. But under that same iTunes file menu you must also go to the "Home Sharing" pull-down and select "Choose Photos to Share With Apple TV". You can select All photos, or just specific albums. Maybe worth saying again that this is done from iTunes and not iPhoto.
If you've already done this and still no photos on AppleTV, check to see that your photo file names (previously imported into iPhoto) have valid suffixes (such as photo.jpg). Without that valid suffix, iPhoto on your Mac will show the photo just fine (courtesy of the hidden Type Code embedded in the photo file), but AppleTV will not.
Good luck and let me know if either of these worked.
Thanks! I had done the choose photos to share and chose photo stream, but it still wasn't working. I then explored the iphoto more and downloaded my photo stream to my library and then shared again with phot stream. This has been a process, but slowly more and more pics are showing up! I am excited it seems it is going to work and appreciate you took the time to answer my question!
Have a great rest of your week!