I suspect that this one was meant to heat up (as it is up near the ceiling, not in arm’s reach), and the metal band would expand, then break, dropping its payload on the floor.
Anyway, it’s probably similar to this one from Wikipedia:
“Another type of carbon-tetrachloride extinguisher was the Fire grenade. This consisted of a glass sphere filled with CTC, that was intended to be hurled at the base of a fire (early ones used salt-water, but CTC was more effective). Carbon tetrachloride was suitable for liquid and electrical fires and the extinguisers were fitted to motor vehicles. Carbon-tetrachloride extinguishers were withdrawn in the 1950s because of the chemical’s toxicity–exposure to high concentrations damages the nervous system and internal organs. Additionally, when used on a fire, the heat can convert CTC to Phosgene gas , formerly used as a chemical weapon.”