This could be related to a permissions issue. Try this: go to Settings > Apps > Timehop > Photos. Photos permission should be set to Read and Write.
If it’s set to Never, this would prevent us from showing camera roll content. Grant permission and restart the app. If you still don't see any photo content, try to delete and reinstall the app. If the permissions are set correctly and you still aren’t seeing local photos, open up the iOS Photos app, tap on Search and then One Year Ago. If you have photo content on this day and you're not seeing it in Timehop, let us know!