Gortsby is in a gloomy mood. He is observing the passers-by who seem to have waited for this time of day to come outside.
Dusk, to his mind, was the hour of the defeated. Men and women, who had fought and lost, who hid their fallen fortunes and dead hopes as far as possible from the scrutiny of the curious, came forth in this hour of glooming, when their shabby clothes and bowed shoulders and unhappy eyes might pass unnoticed, or, at any rate, unrecognized.
The time of day is important to the plot because, if the young man who sits beside Gortsby is telling the truth, night is closing in and he will be in serious trouble because he has only twopence in his pocket and can't remember the name or location of his hotel.
Gortsby was in the mood to count himself among the defeated.
The author doesn't explain why he is in such a mood but says it isn't money problems that afflict him.
He had failed in a more subtle ambition, and for the moment he was heartsore and disillusioned . . .
He is alone. He looks sufficiently prosperous. He could easily be taken for an easy mark by someone who was looking for a person to con out of a bit of money. His body language gives him away. He does not look bowed and furtive, like so many of the others who are out walking. In fact, Gortsby seems to be inviting strangers to come and sit beside him by the indolent way in which he is reclining on the park bench and watching people come and go with a somewhat superior air.
There are still plenty of small-time con artists who spend their entire days approaching strangers and striking up a conversatiion. Park benches are among the best places for this scam because they are roomy and available to anyone who wants to sit on them. The trick is to develop some slight relationship and then ask for a small sum of money. In a big city a con artist can collect a lot of money in a day's panhandling. Gortsby assumes that the young man who sits beside him is such a con-man, but as it turns out both Gortsby and the reader are left wondering whether it is the young man or the elderly gentleman who is working the scam.
The cake of soap must have belonged to the elderly gentleman who was sitting beside Gortsby before the the young man replaced him. But the question is whether the elderly gentleman dropped the soap there on purpose with the intention of coming back to retrieve it and then to tell Gortsby more or less the same story about having no money and not being able to find his hotel room.
Gortsby gave the young man his card, believing him to be honest and expecting him to send him back the sovereign he lent him. No doubt he will never receive that sovereign, but that will not necessarily prove that the young man was lying. It might only mean that he was lacking in integrity and decided to keep his money.
A sovereign was a coin worth one pound. A pound in Saki's day (1870-1916) was worth five American dollars, and five dollars had the buying power of at least twenty dollars today.