While trading demo the person may not put much effort instead will have that mindset that it's only demo therefore has nothing to lose from the trade but with live account the trader will be extremely cautious.
Testing the waters on a live account with small capital will give you an experience that'll have more exciting but traders shouldn't underestimate demo accounts as they're there for a reason. We should use demo to practice all our trading strategies and make our skills to be perfect before going lives. Losing a trade can motivate you but not everybody has the toughest skin to take losses and turn them into profits. Some traders lose their self confidence after they lost some trade therefore before putting yourself out in the real market, we should have had enough practice in the demo account to make our prediction to be more accurate and less of assumptions.
I know that Demo is for a start-up phase and will also guide every single trader who is willing to learn and expand their knowledge of trading to be fruition, but at some moment we shouldn't feel that relaxed in it because it's also something that could give us that weakness to not put much efforts while doing. For instance, when you starts building your trading account with all confident and even though you are being swept off you wouldn't attached more value to it because you think that it's not a real account hence your fund would be topped up immediately after exhausted it without even thinking that in live account you won't have that privilege to be topping balance that easily and you know whatever that comes with real money always have some tension attached with it.