Because an iPhone and an Android device have different operating systems, you need a third-party app to share photos from one to another. For example, you can use a cloud service (e.g., Google Drive, Google Photos, DropBox, etc.) to store and share your photos. Upload them from the iPhone and share them with the Android device owner. You can also with a messaging or email service or a USB-C cable to upload the photos to a computer and then download them on the Android device. If you want a dedicated photo storage and sharing app that grants access to both iPhone and Android users, try Mylio. It’s a free and multidevice app that will sort out your problem in seconds.