According to Apple’s technical specifications for the devices, all new iPhone 15 models support DisplayPort via USB-C, delivering up to 4K 60 Hz HDR video to an external display or TV.
In contrast, previous iPhones with a Lightning port were limited to video mirroring at 1080p with Apple’s Lightning-to-HDMI or Lightning-to-VGA adapters. Currently, there may not be many scenarios where this would be particularly useful, but it certainly opens up possibilities, such as running something similar to iPadOS Stage Manager on external screens with an iPhone.
