Someone used the fact that the upper case letter of “i” looks the same as the lower case letter of “L” to create a fake account that looks exactly like @Jackoplane. The fake Jackoplane is actually Jackopiane, but because “I” and “l” look the same, you can’t tell the difference between those two names.
The easiest way to check if the tweets come from the real or the fake profile is to look at the follower count. The real Jackoplane has about 11’000 followers, the fake JackopIane has around 100 followers.
So if you see a message from Jackoplane on Twitter, always check which one of them tweeted the message.