Ball is related to Bright. Bright is related to Spark. Spark can cause/lead to Fire. Fire is related to Radiation. 
Picture is related to Sign. Sign can be used for Identification. 
Ball <--RelatedTo--> Bright <--RelatedTo--> Spark --Causes--> Fire <--RelatedTo--> Radiation 
Picture <--RelatedTo--> Sign --UsedFor--> Identification 