The layouter is showing bizarre behavior. I managed to get one layouter (mosaic) to work and it does what it is supposed to do. Though I have trouble inserting a new item between 2 items where I want it. I ended up putting the new item finally at the end of the deck.
Then I decided to put a second layouter (mosaic) in another section below a video. It is just bizarre how it rearranges. There are only 2 items in that layouter. I tried adjusting margins, docking, alignments, putting the layouter in a new container etc hoping I will get it to do the right thing upon resizing the window. But it seems to have a mind of its own. There are too many parameters given for customization in the properties panel and figuring out how it is going to behave when you change width, height, docking etc is mind boggling. All I care about in a layouter is the spacing between items (horizontally & vertically) and the margin around the whole layouter. Everything else is an overkill.