on the other company (B), you create demand for that product (i.e. for its operation)
thus, under your control, you make company A and B enter a trade agreement
as someone who brokered that deal, you get rewarded (e.g. from brokerage fee, or commision)
sometimes, by having a massive increase in sales, the stock for company A would increase, thus you can sell a little bit of it, which you can later buy back after the stock price goes back down
profit
Some facts:
even though they're your companies, you are a separate entity from them, and they are each its own entity
the money comes from the investors as well as profit, remember that they are separate
no, you cannot just take all the companies' money, since even though they're yours, there are corporate structures and other people at stake preventing that
So you basically come up with some excuse for moving stuff around, then you come up with some excuse to siphon off some of that good stuff.
English is weird. The letter 'e' can be read more than one way, and it is not consistent to the spelling. The vowels in 'foul' and 'soul' are read entirely differently despite the spelling only differ in the first letter (which is consonant).
I wonder if that open up job opportunities..