Cleaning photos

I just optimised about 100 photos on my phone, but as usual it’s mixed everything up now. Photos I took yesterday are right down my camera roll and this picture I created digitally is now number 1.

There must be a logical explanation for what happens but I don’t know why. I’m not a computer expert so I don’t understand the ins and outs of what is going on. Still it’s interesting to see old photos popping up again. Mostly ones I have made into patterns.