Originally Posted by natasha_fawn
Hey there, welcome,
You've almost got it, go to Home>Apps>Pictures, then once you're there press the options button. The menu that pops up should include a "Select Standby Screen" option, press that, then select each photo you want as a standby screen. Then click Done in the upper right corner.
The key here is to click "Done" when you finish. Clicking return to previous on the top left discards the changes.