Yah so what it does is try to find a path with bidirectional links, and then if it can't it tries to find a unidirectional path. You can tell which one it did by whether the numbers in the path have a pulsing glow animation, that particular path does not.
A few years ago I made something similar (http://ratewith.science/) that only uses bi-directional links, that is pages that both link to each other, and this gives much more interesting results.
When two Wikipedia pages both link to each other they are usually related in some reasonable way, but unidirectional links give you things like Wikipedia -> California, which only exists because Wikipedia is headquartered in California, a pretty weak connection.
Other than the fact I have it running on an overburdened tiny VPS, my app is also really fast even though I only do a unidirectional BFS because I use a custom in-memory binary format that's mmapped directly from a file that's only 700MB, and a tight search loop written in D.
Despite its impact on our lives it's important to remember that tech makes up just one segment of our massive economy. I have yet to see Google get into Aluminum smelting, residential construction or toothbrush manufacturing.