How to solve the photo issue on iPhone 6s?

I do quite a bit of selling on Ebay so take lots of photos on my phone. Since I got my phone earlier in the year, I've been struggling to sort this out.

When I take a photo, it works fine as I can see it in my phones album as a picture.

When I connect my phone to my pc and browse in the folders to copy the pics to my pc to use, they show up as movies or movie clips.

No mater what setting I've used on my phone camera, they appear in the folder (on my pc) as movies.

P.S: this is my first ever iPhone