One of the most frequently asked questions about iPhone cameras is why the photos are flipped. The answer is actually quite simple and has to do with the way iOS devices are designed.
When you take a photo with an iPhone, the camera sensor is actually rotated so that it's in the correct orientation for how you're holding the device. This means that when you take a vertical photo, the sensor will be rotated 90 degrees clockwise. And when you take a horizontal photo, the sensor will be rotated 180 degrees.
This may seem like a strange design decision at first, but it actually makes a lot of sense when you think about it. First of all, it allows you to see the preview of your photo in the correct orientation on the screen. Secondly, it means that when you share your photos with others, they will appear in the correct orientation for them as well.
So next time someone asks you why their iPhone photos are flipped, you can now give them a very satisfying answer!