This means that the vertical alignment of a row should always be set in the cell which has the most lines, because this one corresponds to the actual row height (and any other multiline cells should be set to the default Top). Not precisely, but maybe more intuitively, you can also say that all the other cells in the row are positioned in the way you specifiy the vertical align of a multiline cell. Look below for examples of a middle-, top- and bottom-aligned three-line cell (the baseline is what is highlighted yellow). The effect is that it looks as if all others but this cell are middle-aligned. I.e., if you have a cell with three lines in a column, the vertical alignment middle will position this cell in such a way that the middle of this cell (the second line in this case) will be on the baseline with the other cells. Vertical alignment means here: the current cell is aligned with respect to the baseline of the row. Rather than that, the settings have a visual effect on the remaining cells in the current row. The vertical alignment does not apply to the given cell in the sense that the content of this cell is then positioned vertically in the cell as specified (this is what word processors usually do). "Bottom", for this whole column), the alignment itself applies to the current row. 
if you have a fixed-width column, you can only set one vertical alignment, e.g.
Even though the setting of the vertical alignment applies to the given column (i.e.
0 kommentar(er)
