I browsed the website suggested and found that not that many people actually designed wireframes the way that I always thought wireframes were supposed to look.
Wireframes depict the relationship between the three components of information design, navigation design and interface design. They’re simple and don’t usually get seen by users or clients. Wireframes are traditionally composed of blank boxes, but research has shown that many people add rough sketches to these, perhaps in order to convey more clearly what it is they’re hoping to achieve and providing the user with something quick, simple and very similar to the end product; sort of like a merged mockup and a wireframe. I personally would keep wireframes separate from mockups, as wireframes are almost purely for the designer to sketch the layout, dimensions and navigation, whereas the intention of mockups is to show the client how the site will look when completed.