The version you've installed is the PWA (Progressive Web App). It's effectively just a stripped-down browser window that loads the mobile site in its own dedicated "app" on your device, even though it's technically just a separate Chrome window.
For a lot of users, this may be all they need. But because it's just the mobile web page, you won't get any extra features that you might find with a dedicated app (like notifications or custom UI elements).
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