To keep in proportion?
I have ordered a lovely maxi dress, but it's a bit too big, also slightly too long.
If I order a size down, I'm hoping it fitting better with stop it "dropping" as much, but will it also be a fraction shorter?
FWIW, I'm 5'7", when did that become short?! Over the last few years, lots of things are too long for me, when I used to have the opposite problem.