Much of this movement is to regulate the contents of the cell. This includes bringing material into the cell from the extracellular environment or the plasma membrane (endocytosis) or releasing material made within the the cell to the outside (exocytosis).
It really is an easy project...it just takes a little time. All and all, it took me about 6-8 total hours to make 4 bouquets, 10 bouts (my mom made those though) and about 15 centerpieces. I made two bouquets the day before our wedding and the other two the day of the wedding.
Plus, pre-wedding events, like bridal showers and bachelorette parties, are great for building momentum for the main event (aka your wedding). When a bridal shower is, say, six months before your nuptials, your guests' excitement for your wedding will likely die down well before the wedding invitations go out. Throwing a bridal shower less than a month before the wedding day also isn't ideal for a few reasons.