question about the interface in the new release

In the previous version I had managed to also change the size of thumbnails, making a small space between the control bar and the thumbnails container, making a change in the xml,

<layer name="skin_control_bar" keep="true" type="container" bgcolor="0x000000" bgalpha="0.5" align="leftbottom" width="100%" height="40" x="0" y="18" y_shown="18" y_hidden="-42" zorder="3">

changing the default 20 in Y and shown by 18.

I tried to make the same in the last release but I could not do
can see a screenshot for understanding
I want to make the same , please help me
Ramiro

thanks Klaus
Can you explain me in detail that I do
in ´controlbar_offset' any value that I put nothing happens
is more I can remove it and nothing happens even

thanks again