No, this is very poorly described.
Investing is the act of putting money into something for a potential profitable return. There are many ways to invest. Long-term holding and short-term flipping are both forms of investing. Whether or not something qualifies as investing has nothing to do with the time-frame.
The presence or absence of dividends does not make something an investment.
What is actually done by members here is called arbitrage. Arbitrage is buying something in one market, or at one time, and selling in another market or at another time for a profit. Arbitrage is a form of investing, and it's irrelevant whether it's a long-term hold or a short-term flip, other than doing the short-term flip for a profit means you get your investment and your profit more quickly. Whether long or short-term is more of a mentality or approach that each individual decides, hopefully based on the situation.
As a community we need to get away from saying that one approach is absolutely better than any other. There are as many approaches to investing as there are people. Some approaches are better in some situations than others. It's always situational. Posts like the one I've quoted smack of there being an overall quality difference between flipping and holding things long-term. There's not...it's a preference and both can work in different conditions and different situations.
Personally my approach is best described as neither of these, rather my approach is all about hitting a target return, regardless of how long that takes. Practically though given that my target return is 30% profit, I trend towards the flipping end of the discussion.
Also, I think comparing what is done by members here to stock trading is a really bad comparison. It's really nowhere near the same thing for many reasons. Part of the reason we're able to do what we can do with LEGO and generate profits is due to limited limited production, limited distribution, and limited knowledge in the market. A better comparison is a commodities market, but one where you have to take actual physical delivery of the commodity.
As far as the original topic of the thread, I have no idea what you're talking about. That might mean nothing, but it's probably significant given that I've spent most of my career working in IT for financial services firms (~25 years), and I currently own a consulting and training company that specifically consults on technology and training issues for large financial services companies, so generally topics in that space are something I'm fairly familiar with.