How do I see photos uploaded directly to icloud.com web page on my iPhone?

If you have iCloud Photos turned on in your phone, they should sync to the phone and you view them in the Photos app. See: Set up and use iCloud Photos - Apple Support

On an iPhone, iCloud is designed to be viewed by using the apps on the device (e.g., the Files app for iCloud Drive, the Photos app for iCloud Photos, the Notes app for notes, etc.).

If you are trying to view them by logging into www.icloud.com from an iPhone, note that you can access via a browser varies by device. See: Which iCloud.com features are available in the browser on your device - Apple Support