The iPhone Mirroring feature appeared with macOS Sequoia and lets you screen share your iPhone on a Mac in a way that’s never existed before. It’s like running a virtual version of your iPhone right there on the Desktop. However, you may encounter problems getting iPhone Mirroring to work because of the many requirements and settings.
Check the requirements
To use iPhone Mirroring, you need iOS 18 installed on your iPhone as well as Sequoia on your Mac. The Mac must be an Apple silicon model (M-series processor) or a later-generation Intel Mac with a T2 Security Chip. Fortunately, few Intel models that lack that chip can even run Sequoia, so you’re unlikely to come across that scenario.
Read more at Macworld.com