If you don't know much about chuppahs, as I didn't, until doing an interfaith wedding last summer, stay tuned.
I did a little research (source) and found this:
Chuppahs are comprised of a cloth covering and 4 poles or supports to symbolize the home. The open sides represents having an open home for hospitality to friends, family and guests alike. It is empty (lacking furniture) to symbolize that the base of the home is people, not possessions. The cloth covering represents God's presence over the marriage. (There are some variations to this symbolism. This is just my interpretation.)