Some terminal displays can be resized while a program is executing on it. One example, is the standard XTerm used in X. If the resizing operation sends a SIGWINCH signal to the application (in this case Ved), the buffers (windows) currently being displayed will be resized to conform to the new terminal size.
If you create a window smaller than 8x6, Ved will signal itself, attempt to save any modified buffers (this action depends on the various death RC options, see Section 19.4). Since the terminal is now to small to view anything useful, no error message are displayed. Note that you can still minimize the window, just to shrink it too much.
If the terminal does not send SIGWINCH, Ved and ncurses will be unaware of the change in size. If the terminal supports an ioctl() call to fetch the window size, you can force the windows to resize with the [Esc][Z] function.
If you are using a dumb terminal or another display which does not support either of the above, Ved or the display will most likely crash if you resize the terminal.