Earlier quoted context omitted.
where are you seeing Looker being used?
Looker is powering all the iframes (any 404s should be fixed now). Bigquery is hosting the data, but Looker is generating the queries and visualizations of the data.
edit: ah, I see, it is just one of the partners they have with BigQuery and they are apparently using it for their website (I'm guessing because Looker lets you iframe graphs directly into the page for free).