mmr system is more generous to newer players to the game mode, you are more likely to experience high and low gains in order to quickly find where you belong, if you go on a 10 game winning streak or some outlandishly high amount of games won to losses, its not unexpected.
in addition you have separate MMR per game mode, some diamond player who has never even considered normals, suddenly goes to play normals, will be grouped with other "new" players to the game mode and other players who have a very similar MMR rating, whatever the value is.
in this case i would assume its a combination of things like your team mates have been on streaks, or you are in a pregroup with someone or someones which raises your overall average MMR for the team.
as a whole your teams MMR must be similar to the enemy teams average MMR, maybe they've been on a bad losing streak?
in addition im not looking at what game mode this is, so it might just be custom or pregrouped teams etc etc, at which point MMR goes out the window.
edit -
also i just checked your match history, you weren't in this game or it happened so long ago that it cant be searched for(which isn't the case as i see curse voice advertisement). dont take pictures you find off the internet.
