[Loriel]

The style is that of the other icons in the screenshots. It's the gtk default icons, I think.

The Create Link button turns the current selection into a link. Like, the thing you walk on to get to another level or whatever. The Show Links button shows a window with a list of all links in the current level.

The Show Signs button shows a window with a list of all signs in the current level.

The Show NPCs button shows a window with a list of all npcs in the current level. The Create NPC button adds a new NPC with an empty script and image path.

The Show Tilesets button shows a window with a list of all the tilesets that are active in the current level as if by addtiledef or addtiledef2 or however that works.