For me the difference is the length of time I feel like that. So for me, I can only let myself totally withdraw for a day. I love my own space so I do partially withdraw for part of most days but only after getting up and about to do something.
if I let myself withdraw for longer it looks like this:
Day 1 - feel a bit blah
Day 2 - depressed
Day 3 - mixed (hypo and Sui)
You may be able to withdraw for much longer. Unfortunately, I flip between moods very easily.