Mastery Spam. Is it toxic?

Personally, I rarely find an opponent flashing their mastery after every play to be toxic. I do sometimes wonder why they bother (I don't do it myself because I'd rather be playing than taking time to hit the correct keys to taunt people with my emote), but I don't find it particularly toxic. However, I had a game today where the enemy team's jungler, every time he made a decent play, would flash his Mastery 7 emote. No big deal. Then around the 10 minute mark, he tried to gank our toplaner after the enemy toplaner recalled. I was heading top to try to help since our toplaner was low, so I got to see the whole play. He came in, got outplayed, died 1v1 against a half-hp opponent, and our toplaner flashed their Mastery 4 emote over his corpse. It was the funniest thing I saw all morning, and amazingly, it legitimately tilted the enemy jungler. He spent the rest of the game chasing our toplaner all over the place no matter what else was going on, diving turrets, getting caught out and falling into our ambushes, and generally feeding the whole rest of the game.

It made me wonder what the point of these emotes are besides being a troll to other players. With several new emotes coming soon I hear, I wondered. Are emotes good for anything other than being toxic/trolling people?