no live histogram when tethering?

When shooting tethered, I'm not getting a live histogram display; instead the 'exposure evaluation' window shows the histogram of the last photo I took. This makes no sense to me, I'd say whole point of 'evaluation' is to show the effect of changes to settings like shutter speed and aperture. To see the 'live' histogram, I have to walk over to the camera and look at its LCD display.

Surely, I'm missing something here. We have 'live view', but where's the 'live histogram''?