iTunes is not used to transfer photos from an iPhone to a computer. It can transfer photos the other direction (computer to iPhone).
See the instructions below from Import photos and videos from your iPhone, iPad, or iPod touch to your computer - Apple Support for instructions on transferring from iPhone to computer:
Before you import your photos and videos:
When you import photos and videos from your device to your computer, some might be rotated incorrectly. To play videos on your computer at the correct orientation, use iTunes for Windows.
If you can't import your photos to your computer, or your computer doesn't recognize your iPhone, iPad, or iPod touch as a camera, learn what to do. Windows XP might not be able to import videos larger than 500MB without iTunes installed, a third-party program, or updated drivers.
Learn how to import photos and videos for Windows 10, Windows 8, or Windows 7.