Depending on if there are caps, or where they are/how arranged, here we go on text exotes:
1.)
o.o : blank stare, as in "You've just lost me" Or "I care about this...Why, again?"
2.)
O.o ; o.O : Confusion, usually used together.
3.)
O.O : Suprise, shock.

"allow it" means to just leave something alone, or don't worry about it. People in West London say this quite often.

An anime style smiley used to express shock, or

shock, puzzlement, misunderstanding; raised eyebrow, skepticism

generally used in online chatting

A surprised, disturbed or confused emoticon.

it depends. either you use: o.o, O.O, O.o, or o.O there's a good chance it's for something you couldn't believe you just heard.

–emoticon

1. A commonly emoticon used on the internet to indicate confusion
2. A surprised look
3. (used to specify the feeling where you don't know what's going on)
4. Over-used in instant conversations like the internet short form of laugh out loud; "lol".

This emoticon has been used in several different ways. Some of them, you may recognize:

o.o , o.O , O.o , o_o , o_O , O_o , 0.o , o.0 , o_0 , 0_o , 0.0 , O_O , 0_0 , O.O

Aside from the ones given above, there have been several people who customized them. For example; o_______o , o_o;; , o_o" and so forth...