Alternate scoreboard on Studio?

So I was just testing my Settings GUI I made to see if the settings worked, I play tested it and walked aimlessly while interacting with the GUI. Then, I realized that the menu buttons (the Roblox button and stuff) was non-existent, and the scoreboard was replaced with a text. I clicked on the scoreboard, and I think it shows some player info for that scoreboard? I quickly stopped that session and tried to start the game again using the play button from the HOME tab (I was running the game in Device Emulation HD 1080 mode) but it returned back to normal.

Does anyone know what this is? I’ve never seen this UI before, and it kind of scared me because of that. I haven’t found a way to reproduce it either.