It is assumed that the left hand is holding the glass and resting it on the armrest.
It is necessary to make adjustments as appropriate, such as changing the position of the arms and the angle of the knees according to the shape of the chair and the body shape of the person.
左手はグラスを持ち肘掛けに載せている想定です。
椅子の形や人物の体型に合わせて腕の位置や膝の角度を変えるなど、適宜調整が必要です。