Window width should remain the same
Window width is decreased

Operating system: Win 7 / Arch Linux
Version of Telegram Desktop: 1.1.24 alpha
Used theme: Any
The same problem here. Also, please, take atention to the icon. It gets dark on dark background sometimes.
I think we need a feature to completely disable this annoying panel.
@aNNiMON In this GIF the first closing is correct (the column was showed with the window being expanded and then was hidden with the window being shrinked), but the second one is a bug (the column was shown "inside" the window, without chaning window size, so it should be hidden the same way).
@khorrth This depends on the color theme used. But perhaps I'll change the used key from the active buttons background to active text foreground (so that those icons would have the color of clickable links by default).
Most helpful comment
I think we need a feature to completely disable this annoying panel.