Hmm, I'm not too sure on that myself. I've never heard anything about them not liking being able to see each other (though certainly possible), only that it's generally not good to actually house them together in one setup. Not positive on this though so don't take my word for it.
What I really wanted to say though, be careful putting a new snake so close (even in the same room) as one you already have. It's always a goo idea to quarantine new snakes in case they have something contagious to other snakes, commonly mites but IBD is a big concern though rarer I believe. It might sound extreme, but it's good to keep them quarantined for 2-3 months or so in a different room to make sure they are completely healthy before exposing them to your other snake(s).
Congrats on your new addition btw!