Get files in Web directory and show thumbnails

WEB TMS WEB Core
24

I have attempted the following but get a row count of 0.
I also used the AResponse for JSONObject

The grid is populated but what am I not understanding on this please.

procedure TForm1.WebHttpRequest1RequestResponse(Sender: TObject;
  ARequest: TJSXMLHttpRequestRecord; AResponse: string);
  var
  I : Integer;
  JSONObject     : TJSONObject;
  JsonArray  : TJsonArray ;
  ArrayElement: TJSonValue;
  FoundValue: TJSonValue;
  Result : String;
begin
      JSONObject := TJsonObject.ParseJSONValue('[{"Picture":"UPVC1.jpg"},{"Picture":"batteries.jpg"},{"Picture":"DewaltOrbitalSander.jpg"}]') as TJsonObject;
      showmessage('json Count = '+ JSONObject.Count.ToString );


         try
     for I := 0 to JSONObject.Count - 1 do begin
       WebMemo3.Lines.add(Format('Key=%s Value=%s', [JSONObject.Pairs[I].JsonString.ToString,JSONObject.Pairs[I].JsonValue.ToString]));
     end;
     finally
end;
end;