Okay kiddo, so a dog and pony show is when someone puts on a big performance or presentation to make something seem really exciting or important. They might use fancy lights, music, and lots of talking to get people interested.
It's kind of like when a circus comes to town and they have all these cool animals and acrobats doing tricks, and everyone goes "ooh" and "ahh". The people putting on the show want everyone to think that what they're showing off is the best thing ever, even if it's not really that amazing on its own.
So sometimes when someone is doing a big presentation or trying to sell something, people might call it a dog and pony show if they think it's more about flashy presentation than actual substance.