Q. If during tekias shofar during the days of Elul one notices someone that is seating down, should he admonish him and tell him to stand up.
A. The blowing of the shofar during the month of Elul is a minhag mentioned by the Tur and Remah (O.H. 581: 1), and one of the reasons given is to awaken the people to pay attention to the imminent and impending coming of the Days of Judgment and the essential need to do teshuva.
The minhag and tradition is indeed to stand up at the time of the tekias shofar (Piskei Teshuva Nitei. Gavriel 3: 10 and others).
Horav Shlomo Miller’s Shlit’a opinion is that if someone has difficulty to stand he may remain seated. However, if the seating is due to the lack of consciousness and care for the impending Yom Hadin, he should indeed be reprimanded.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller and Horav Aharon Miller Shlit’a