What is the basis for the permissibility of using images on currency?

The Shaykh : But there remain coins called French francs; I do not know if you are familiar with them or not? They are called French francs and they exist. In any case, if you do not have them, we will bring you a franc so you can look at it, and it will be returned to us, if Allah wills. This one has an image of a person, and a disbeliever, and it is raised, meaning it is embossed. The scholars have permitted them for people since ancient times. And there is a gold coin called the French pound, which has two images: on one side, an image of George, the King of the English, and on the other side, a knight on a horse. You can see it and touch it with your hand. People used to pass these pounds around, and the scholars permitted it for them. So what is the basis for the permissibility? The basis for the permissibility is dire necessity. People cannot leave these currencies, and a person cannot relinquish them. But I have seen some people, when they stand to pray, take out the coins they have with them that bear the images of kings, and place them in front of them, meaning instead of keeping them hidden in their pocket, they pray toward them. Which is greater, the second or the first? The second. But if someone comes and picks them up, is it permissible to break one's prayer to catch up with him? Yes, because this person is trying to take his money.