What does のそ mean in this picture?
A friend of mine said that it was "a moment later...", but I'm not really sure if that's the real meaning. What does this annotation mean?
「のそ」 is an onomatopoeic word describing a slow and/or sluggish kind of walk or body movement.
We also use 「のそのそ」 and 「のそりのそり」 as its variants.
You can forget "a moment later" for good as it has no such meaning.
For the onomatopoeia-curious out there, 「きびきび」, which means "chop-chop", "speedily", etc. would be like the 'antonym' of 「のそのそ」.