"If a human can't theoretically perform the task with a lot of time and a pocket calculator, then neither can an AI."
But it's not really saying much as that applies to almost everything.
As for the core idea of designing AI UX better to get people to trust it - maybe put a list of all the data being collected and stored up front, and make it possible for the user to easily and permanently delete specific data while still allowing them to use the system. Also an explanation of actions taken: "the system took this photograph because 76% of testers found photographs with these particular features (high light level, human looking at camera, action) to be desired." You could probably trace your dataset back to these features by collecting all the photos from training that matched to those features and manually labeling them.
In short: un-black-boxify your UX.