the code you are using is not fully right. a datagrid needs to have a source / dataprovider. i dont see that in your code.
you can create an array collection and using the object as your source
you then set your datagrids dataprovider to this arraycollection. one quick way to access your object is like this ( using binding )
About your image. datagrids dont show images by default. you will have to create a custom renderer for your datagrid to show images. look into the documentation on how to create a datagrid item renderer.