The one on the right looks like different buttons and that everything is clickable. A quick glance shows you different elements and you can easily find what you're looking for. An example of form and function working together.
The one on the left looks like a text area showing different symbols. A quick glance shows you a blue area and a white area. Seems like you need that extra moment to find what you want because everything looks the same. An example of function over form.
Cramming a lot of things together isn't always good (probably it's just bad in general) because it just makes things confusing and ends up wasting time more than having bigger things but less of them.