On their free time they do tutorials about their process, their tools, etc.
Saying that they are a retail trader is like saying that Warren Buffet is a retail trader when they trade with their own private money and not the money of their clients.
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Also, you can just open a paper trading account and trade with fake money. Then the screenshots look real.
I do this all the time when I need to explain an options play to somebody. Just switch to paper trading, give yourself a million $, and enter the trade.
If I had to show somebody in a podcast how to trade, I would open a paper trading account just to put an amount of money that would be reasonable for that person, so that they can better get a feeling of what the wins and the losses look like.
I'm not saying I feel strongly either way, but I think peopel on the internet lying is a pretty simple explanation.