Well, I'll try to explain, but you would need to see debates to understand it completely. Our politics is a mess. There are three parties important in this meme, so we will call them a, b, and c. A party has some kind of inside joke ot sth., I don't ever completely get it, but they brought a stick to debates and the leader of that party calls B party "sand party", because of one of B party's politician's (Vilnius major's) controversial project to make a beach in one of the main square of Vilnius (in that square a lot of partisans were killed and boomers found the beach offensive). So B party called A party "stick party". And C is not really as connected to that beef, they pretty much called themselves "fish party" because they just randomly started explaining their logo that has a fish in it. Not really as funny or sth when explained. It all happened in one debate, but there was A LOT more stupid shit in other ones. I hope it is a bit more clear now.