Yes. For optimizing you need to add Alt Tag, Image name and resolution. Try to use large resolution and resize by yourself. Image name should be like - Warrior-Forum-Members.jpg or png instead of Warrior Forum Member. You should use "-" without quotes.

Take this article on optimizing images for search

Obviously they should be unique. Unless, I'm missing something here?

Yes, image optimization should be unique for each and every image on the website. Only then, it would add value to optimization.