Besides, I never said it was "obvious." That's giving both Lois and Clark too little credit. What I said was that Lois, who is a skilled investigative reporter and keen observer, was able to apply her skills and discover something that was hidden from most observers.
Sounds fine, except that we don't really see her DO any investigating or use any skills (like digging into Clark's past, for example). All she does is notice that the picture of Superman in the paper looks an awful lot like Clark when you draw a suit on him.
I get that she's a smart reporter with good instincts, but I doubt she's the ONLY one in the office who could put 2 and 2 together like that.
Yeah it does make her seem a lot smarter and sharper than how the Lester version did it, but jumping out a window-- even with Superman around-- is just a completely wacky and bizarre thing to do.
If the scene had stopped before that, and just had her continue to eye Clark suspiciously for the rest of the movie, it would have been MUCH more appropriate and believable for the character, I think.