Chosen Solution
I have 100 pictures/ videos on my phone. I have never had a problem transferring them to my computer. The pictures show up on my phone but when I connect phone to computer only about 20 pictures show up. Where are the other 80?
The others are likely set up on iCloud and will have to be loaded off iCloud.com.
Maybe you can try a third-party program to help you transfer pictures from your iPhone 6s to computer. My suggestion is Coolmuster iOS Assistant. After linking your iPhone 6s to computer via usb cable, it will scan out all data on it. Then you can choose pictures you want to transfer to computer directly.
