Slovakia played very well on the last Euro and they knew how to play on result. One of the reasons is their experience - there are many veterans in the squad and the core of the team is the same - Dubravka, Kucka, Pekarik, Duda, Hancko...
From the other side, we have Estonia, a team that is among the weaker teams in Europe, no matter that they won the Baltic Cup in June that could be a signal that there's some improvement. They beat Faroe Islands and Lithuania on penalties, so Slovakia will be too big pie to swallow.
Slovakia is one of the best teams in League C, so they will look for that option for another placement on a big tournament. Sweden is also one of the strongest teams in League C and they're in the same group, so Slovakia will do everything to start with a win, not to lose points against the weaker teams in the group Estonia and Azerbaijan.