As an AI language model, I can provide you with a basic outline to start creating a third-person open-world shooter game using HTML, JavaScript, and pictograms. However, creating a full-fledged open-world shooter game with detailed graphics and a compelling storyline is a complex task that requires significant time, resources, and expertise. Implementing such a game as a single HTML file might not be feasible. Nevertheless, here's a simplified example to help you get started:
Please note that the code provided above only renders a basic game canvas and displays a placeholder pictogram for the player's character. To create an actual game with advanced mechanics, graphics, gameplay, and a storyline, you would need to delve deeper into game development frameworks like Phaser or PixiJS.
Furthermore, optimizing the game for specific devices and achieving compatibility across various smartphones can be an extensive process that might require additional steps and considerations.