The size of this Wordsquare is
..either 2×2 (as explicitly said) , 3×3 (if the last stanza means something) or 4×4 (if the last two lines each are up to something
My first is in a gift, a representation of what you are
This may refer to present, which refer to the gift and the word are.
My second not so much a gift,
But a representation of what you were.
Using the same logic, this refers to past
But that is way too long a word for a Wordsquare! Well,
It can be fitted using the Japanese letters, or something like that. I must stop here, since I know nothing about Japanese, and I might be completely off-track.