The reason why the flag is flown with the hoist on the left is because of the writing on it. The centre text says "Kuwait" or "Koweit" as it was also called at the time, and the text on the hoist is a declaration of faith in Islam and says "There is no God but God (Allah), Muhammed is the messenger of God". I couldn't find what the arrow-ish symbol or the two lines meant.
Source: https://www.crwflags.com/fotw/flags/kw_emir.html#940