Altimeter indications at both locations are same though the heights above sea level are different.
An error in the pressure altimeter resulting from a difference between the prevalent barometric pressure and that in the standard atmosphere. The local barometric pressure is corrected to sea level on the subscale, or veedor counter Kollsman window
, before or during flight. The aircraft height even after this correction will vary if it flies into an area of higher or lower pressure. For this reason, during cross-country flights above the transition altitude, standard altimeter settings (1013.2 hectopascals, 760 mm, or 29.92 in) are set. (See also Kollsman window