If points T and T' have the same x-coordinate after reflecting point T over a line of reflection, this indicates that line of reflection is vertical (a vertical line). In such a case, the vertical line of reflection is positioned vertically between points T and T', preserving the y-coordinate of point T while changing its position horizontally.
To summarize, if T and T' have the same x-coordinate, it means that the line of reflection is vertical (i.e., it could be of the form x = a, where 'a' is a constant).