When I logged in i teleported and had a fuzz black and white screen and saw a clone of myself??? in creative

It is more of a glitch then a bug. Its never happened before, i logged into a LAN world that my friend was hosting and i got teleported to somewhere about 100 blocks away and had a black and white squares screen flickering from my minecraft to that screen for about 5 seconds. Then when it stopped i was back to where i originally was and saw a steve skin clone of my self with my username, and when i spoke in chat, there were to of thee messages that i had sent with the same username??? ..... heres a pic of 'it' and me -->