Maybe only editors see that. You can to go a game page of your and select 'Upload or Manage Files' from the black box towards the bottom. But that will associate the graphics with the game in question.
But if you are trying to show board diagrams, you should not upload anything. Use the Diagram Designer which will give you a link which generates the picture dynamically so no extra files are stored on the server. This is what Kevin has done for his diagrams. Since this converstion topic is not associated with any page, any files it references will be stored in some arbitrary location and will take up server space forever and we won't even know what they are used for.
Maybe only editors see that. You can to go a game page of your and select 'Upload or Manage Files' from the black box towards the bottom. But that will associate the graphics with the game in question.
But if you are trying to show board diagrams, you should not upload anything. Use the Diagram Designer which will give you a link which generates the picture dynamically so no extra files are stored on the server. This is what Kevin has done for his diagrams. Since this converstion topic is not associated with any page, any files it references will be stored in some arbitrary location and will take up server space forever and we won't even know what they are used for.