I don't see how it got it wrong (and it would be surprising if it did given the sentence is not syntactically ambiguous). It does use a visual notation which, AFAIK, differs from the standard in linguistcs [0].
This site is producing dependency parses, which have become popular in the last 10 years or so. The linked figure is a phrase structure parse, which used to be the thing everyone worked on but have since turned out to be both harder to get and less useful than dependency parses.
[0]: https://en.wikipedia.org/wiki/File:Syntax_tree_for_Colorless...