ok, i took my time now to watch the video and read all the stuff they wrote.
I won't mention the things that can be seen in the background like xp bars and such, i guess they will be explained in a later movie.
Basically what they showed is mostly not that different from im@s 2. It seems that, as time goes on, you'll get more and more of the girls to work and have conversations with. About these conversations: it looks like they are more or less set events which increase the memory gauge for the selected idol. I guess they are similar to the story events for your main idol in im@s 2, but this time you can have them with more than just one.
In the morning you will be greeted by your idols, as shown in the video twice. It seems how this greeting exactely looks like is random. You'll also see the idols going on about their daily life in the office while you are fiddling around with the menu. And the idols who stay behind will send you off when you go to work (as shown with Yukiho and Takane).
They said that an important part of producing is to select the correct idols for the task at hand and that the jobs you can accept increase when you rank up. There will still be auditions, festivals, lives and promotions as in im@s 2.
Sometimes the host of an audition will say what he wants to see. In the video at 4:35 he wants to hear their voice, and vocal score seems to be multiplied by 1.5 for a short time.
In the next video they'll talk about the rank up festivals, looks like they are back. In im@s 2 all was determined by the highest rank you were able to achieve in the charts.
I'm really getting hyped for this game now and i'm looking forward to exploring and finding the right strategies with you guys.