First of all, you don't need to have a title. So, only have one if you need it. Sometimes, an image on its own, is an interesting enough way for a visitor to simply start exploring, and discover your stories for themselves.
A title can be used to simply flag name of the object, image or document.
You could also add a logo or exhibition title, if that's what is needed.
Keep it short, this is not the place to say anymore other than the main heading.