Steemit is currently rolling some new updates and features such as the Follow tab and there is a new design apparently, however it seems that the new design does not work properly on Internet Explorer 11 as you can see on the screenshot above. The page in question is the user profile page and the menu is apparently not rendering properly under IE11.
I have tried it on Firefox and everything seems to be just fine.
The same goes for Chrome as well, everything seems to be Ok.
So it seems that Internet Explorer is not handling the new design properly and I have seen some other issues with IE11 before the latest update of things not working very well (some of which are apparently fixed already). So it seems that Steemit has not been tested on Internet Explorer 11 and quite a lot of people still use it in my personal opinion, including myself from time to time...
If anyone else is experiencing the same issue under IE11 please report it in the comments.