Installed web applications can now receive file shares, e.g. images. Using the manifest, the web application can declare which MIME types and/or file extensions it accepts. Previously, mobile platforms allowed files to be shared to native applications, but not web applications.
Docs: https://web.dev/web-share-target/
Samples: https://github.com/GoogleChrome/samples/tree/gh-pages/web-share
Explainers: https://github.com/WICG/web-share-target/blob/master/docs/explainer.md