The disadvantage of a limit sell price is that price may gap below your selling price and your sell order won’t be activated. Your losses can become much larger when this happens.
When triggered, the trailing sell will place a market order to sell immediately at the market price.
The disadvantage of the market sell is that there may not be enough volume at the market bid and the sell order will continue lower until your whole order is filled. If the bid depth is thin, this may cost you plenty if your sell order is large in comparison with the bid depth.
The pictures imply that the TS is used when your position is in profit and the TS protects some of the open profit, while the FS is to be used when your position is losing. Don’t be confused by these implications the sell actions of a market order and a limit order are quite different.
We use the sell method that is suited to our trading style.