update: what I have also noticed, whenever I close laptop lid content from desktop is ported to TV, like TV is taking role of primary display. Re-opening lid reverts situation, desktop content goes back on laptop screen, while only desktop background/wallpaper is displayed on TV.
I don't know if this is normal, but it's definitely not the way old VGN-Z behaved and not the way I want. Closing/opening lid would not affect external display (TV would always show background only).
To be clear what I want to achieve: start movie on laptop, drag movie window over right/left screen edge of laptop to TV (as set to extended display), double click for full screen, close laptop lid and continue watching movie on TV.