A standard error message on Stack Exchange sites looks like this. It's a pop-up that appears if something happens on the page, for example, if the body of a question is missing.
If you try to post another example question in less than 3 minutes after you posted the last one, you get an error message explaining that. So far, so good. But the design style of the error message is inconsistent with the rest of Stack Exchange.
In order for that error message to appear, the webpage has to reload all over again, instead of popping up like a normal Stack Exchange error. And the error message is at the bottom of the page, which makes you have to scroll down to see the red text.
This Area 51 error message is inconsistent with the rest of Stack Exchange. It's also inconvenient since the page has to reload all over again for the error to show up at the bottom.