Whenever I login to my machine some green text appears in the top left saying "Profile". It has done this since OSX Mavericks too.
Here's a screenshot:
This happens because of Razr's mouse and keyboard software that allows you to designate profiles for key bindings. The profile that is being used is displayed in green text in the corner of the screen on when logging in.
Definitely Razer's Synapse software telling you which profile is currently active, as it starts on login, it pop's up on login. It also shows up on profile changes e.g. when you have profiles for different applications, it pops up every time you change to those applications.
Very annoying behaviour and I'd love to find a way to disable that crap (maybe an empty name works, otherwise there's always Controller Mate)
That looks like it may be coming from your monitor and not Mac OS. It's possible that when you login a change in the display settings is triggering your monitor to change "profiles".
I would look through your monitor settings using the buttons on the monitor itself.