Visual is related to Color. Color is related to Stone. you are likely to find Stone in/at/on Pond. 
Lower is a synonym of Diminish. Diminish is a synonym of Decline. Decline is a different concept from Approve. 
Visual <--RelatedTo--> Color <--RelatedTo--> Stone --AtLocation--> Pond 
Lower <--Synonym--> Diminish <--Synonym--> Decline <--DistinctFrom--> Approve 