As far as I know, and how my experiences are, mixed episodes are not about changing between (hypo)mania and depression, but a state where both are present at the same time. It is having very negative feelings, but still have energy (both physical and mental).

You feel irritaded, desperate, full of hate, nervous etc. and interacting with people becomes difficult (or at least it has concequences), because you are neither the quiet depressed one harming no-one actively, nor the supersocial and lovable one, but the worst possible combination created by picking features from both. When with people you act like a clever *****, have all these intelligent insults, which you say because you hate all people and don't want to avoid causing impact. You attack people even deliberately, maybe not because you think you are all powerful, but in your mind full of negative energy the others deserve it - you deserve their hate and despise once you are done with them. To some people you are not able to speak at all (or you should not) because you are so agressive that you know you are not able to answer nicely, no matter how much you try, and you don't want to hurt them because you love them (some other day). Alone you cannot stay still, but pace around the room as tense and desperate about life, and you want to scream and cry and want to smash things. You would like to crawl under the blankets and sleep forever but you cannot because you are too aggravated. The rage inside does not get out no matter how much you scream, insult, cry, smash, yell, run, tear. There is so much of it that it crushes everything else inside you and nothing else fits in the world.
Negative hype.