What happened to my enameled cast iron pan

Hello! I’m not sure if this is the right place to post, so please let me know if it doesn’t belong here 😊

I was cooking up some ground beef for a shepherd’s pie yesterday and seasoned it with garlic, onion, salt, and pepper. After, I added some tomato paste, water, and flour. It came out fine and tasted great!

However, when I went to clean my pan, I noticed that the enamel has discolored. It almost looks like rust? I always hand-wash this pan and dry it immediately, so I’m not sure what happened. Does anyone have any ideas? I think the pan is usable but it just looks a little janky now which makes me sad because it was one of my favorites 😅

Thank you for your help!