How should we know. Gain or loose weight, who cares that is trivial. Do what you want to do. Do not feel you should conform to what you think society wants.

Just keep fucking

Firstly, you have no issues that I can see. Thin isn't necessarily bad unless it is accompanied with some type of problem.

As for putting on weight. Weight for the sake of weight is dumb. If you want to fill out, go to the gym and make it a habit. Muscle is denser than fat so with every pound you pack on, you will be equally trim but more robust and healthy. Be sure to pay attention to all your muscle groups to ensure you grow proportionally and keep fit. As you build muscle, you will need more calories, but eat sensibly and healthy. Lastly, be sure to run and keep your heart in shape. The more weight you carry, the more your heart has to pump to keep you healthy. This is a long term plan and if you keep it up, you will fill out, have a great body, and be a very healthy, desirable person. Good luck.

looks ok to me. work out if anything.