Moon square Saturn (orb 1.1°) creates concrete friction between the two planets. The orb is very tight; this describes a stable character pattern more than a passing reaction.
Here, Moon in Pisces in House 12 brings personal dream, play, inner child, childhood imprint, mother figure, mother image, optimism, and inner rhythm into House 12 (retreat, contemplation, long time, and possible confinement), with Pisces style (imagination, faith, compassion, dream, and permeability); Saturn in Sagittarius in House 8 brings discipline, constraint, endurance, and mastery into House 8 (sexuality, shared power, crisis, and invisible bonds), with Sagittarius style (expansion, travel, belief, and the search for meaning).
Concrete friction: this aspect can make the personal dream and mother image feel supervised by Saturn: play, spontaneity, or childlike confidence meets fear, duty, restraint, or the need to hold it together. House 12 (retreat, contemplation, long time, and possible confinement) is in friction with House 8 (sexuality, shared power, crisis, and invisible bonds); this can create blockage, inhibition, overreaction, or repeated conflict between the two fields.