PREFIX  foaf:   <http://xmlns.com/foaf/0.1/>
SELECT ?person ?nick ?page ?img ?name ?firstN
{ 
    ?person foaf:nick ?nick
    OPTIONAL { ?person foaf:isPrimaryTopicOf ?page } 
    OPTIONAL { 
        ?person foaf:name ?name 
        { ?person foaf:depiction ?img } UNION 
        { ?person foaf:firstName ?firstN } 
    } FILTER ( bound(?page) || bound(?img) || bound(?firstN) ) 
} 