haha! I believe you are very confused because some girls use confusing adjectives when they comment on photos (I must admit that I also do this sometimes
)
when i say
cute i think of a very adorable and...pretty...maybe even fluffy thing
...or something that makes me smile a little. and a
cute pic means that the person in it looks friendly and...pleasant.
'
nice pic' means that I like it, but in a general way... I remain quite neutral, while '
great pic' means that I am more impressed.
'
good-looking' means that from my point of view you have a beautiful appearance.
I don't usually use '
hot', '
handsome' or '
sexy' (for me they all have similar meanings: you are quite attracted to that person
)
But as you said, 'nice' and 'great' have became so common that you'll never know if someone uses them with their real meaning or just because they can't think of sth else to say.