For example we have the following html code:

<table>
  <tr>
    <td id="myelement">
      <div>Text 1</div>
      <div style="display:none;">Text 2</div>
    </td>
  </tr>
</table>

with calling

txt=browser.cell(:id => "myelement").innerText()

we will have txt="Text 1Text 2"
But second div is invisible and user can see only "Text 1".
It is needed to fetch only visible text with new method getVisibleText()