WebDriver allows you do automate tests you would normally conduct manually within the web browser. How would you conduct the test if you need to write out manual instructions? You need to be detailed. You also need to think in terms of HTML, CSS, XPath, javascript and interacting with the DOM. There is no such thing as 'tabs' in any of this. I can use HTML, CSS, XPath and javascript to simulate the concept of tabs on a web page. There are multiple ways I can make this happen. How I automate it is completely dependent on how I implement it.
Bottom line, picture of the web page is seldom helpful. How it was implemented (HTML, CSS, XPath, javascript and DOM) is what we need to look at in order to automate it.