Oops -- I commented and forgot to click the "add comment" button!
The humor is quite remarkable -- you've captured a precisely appropriate moment that matches the quote. It's so good that the moment expands and I can imagine the two birds playing R & J through the whole play (like a "funny animal" comic book version). Strangely, it makes the romance of the story more powerful for me. (Maybe R & J have become such a cliche that even a couple of birds breathe new life into their tale.)
In terms of the composition: the lines of sight work very nicely with the theme of the photo. After a moment it gets somewhat troubling -- perhaps the same way the story of R & J is tragic? That smooth shape at the left of the bottom roof line -- it is entirely incongruous with the architecture and it looks like a large stone.
"Two birds with one stone." That's a tragedy for the R & J in this picture.
Well, Romeo & Juliet played by two birds, I guess it could be a great idea for a Pixar movie. I had a lovely moment taking a look at these birds, because they stayed a long time on the roofs, actually talking to each other, one singing, the other immediately responding. It was at the "Mont St Michel", in France, where tourists only take photos of the Abbey. What a shame
Your series of Mt St Michel photos were also nice -- they made the place feel like Nosferatu's castle in some shots (certainly not the usual touristy shots!). I recognized the roof line from another shot in the series.
The birds in the photo have such distinct personalities!