I am pretty sure that those machines aren't legal but there is much corruption in my country so I bet there is some big fishes making money on bribery allowing that those machines keep working on the corner stores.
Basically, what I know of such machines are that they are used for games. Coins are slot inside to activate access to the games and kids play on them, except if they are now used to do staking and competition for profit or gains. Otherwise, they are machines that children play around with for their different games and those coins are so that it allows access to it and timing for the games.
So apart from that, except there are people who now arrange them for the purpose of gambling for underage. But allowing children that freewill to always jump on the machines can lead to addiction and that could result into gambling or using their upkeep to play.
Agreed, similar machines can be seen all around. Those machines look similar to the slot machines, and I haven't seen machines put for gambling in any of the malls in my locality. As said, these coins provide access to the start of games. Kids enjoy different games, and in my region I've seen machines with different games, and we need to pay to the shop and receive chips that can be used to operate the machines. We can't be sure the same is happening all around, and it is the responsibility of the parents to have a cross-check before letting the kids enjoy playing it.