Not tips. You send Steem to tipu and then their bot follows your command and pays the tips out when you tell it to. A normal tip is 0.1 but you can make it as big as you want by adding the amount of Steem you want to send after the tip command. !Tip
The bot read the amount of ESTM I sent you as a command to send a big tip. It was my error, but I hope you find a good use for the Steem!