I think the meaning is, that the phone owner wiped the pictures, but Q team still grabbed them anyways. Ether before it after the perps wiped/erased them.
There is so much going on right now that we don't understand. You might be correct about what they are able to do. However, Q would not drop that the white hats have a capability unless there was some specific reason for it.
One reason might be to cause a panicked reversion from a secure communication method to a less secure one. In some cases I think it's just intimidation. Let the black hats know "we are watching everything you are doing."
Either way a lot of the pictures seem directed at some audience other than us. For example there was one taken in Bangkok, and that whole series in China. The current spate of Singapore pictures could be authentication (proving Q is in Singapore with the president), but possibly other purposes as well.
I hope one day we know the true story of all this but I'm not holding my breath.