It seems "cute" because it is spelled using only two letters but the phonetics of the world involves pushing your entire tongue back and keeping your voice low like bro why so much effort
It really has no meaning
example:
OMG Aw THAT IS SO CUTE ( YEAH BYE)
OMG AWWW ZAYN MALIK'S EYEBROWS ARE ON FLEEK Aw
AWGH
AWWW
OMG AW STOPING USING THAT