When situations emerge in which various resources can meet users' requirements.
One environment only gives one kind of resource, while the other gives several kinds.
For example: If the query is a person's name, then this is a common enquiry - images, videos and wikis can all meet these requests.
If the top three in the left environment are all images, then the top three in the right environment are images, videos or wikis.
Therefore the right environment is better than the left one