In the last song, "Nothing's Gonna Stop Us Now," Darla inadvertently makes their performance big AND loud—exactly what she was preaching to Danny a few scenes ago.
Taking it a step further, Pudge's sax solo at the beginning is the "little bit jazzy" Darla was talking about.
As pointed out multiple times, this film is a great big metaphor for the hard times minorities faced when trying to get into film. This makes you wonder how minorities are treated in this universe. Then at the film premiere at the end, you can see plenty of black audience members. They're not being forced to sit in separate seats; they're sitting right alongside the white audience members with no trouble whatsoever. It's possible in this universe, the humans, being forced to live alongside anthropomorphic animals that are radically different from them, were able to get over their prejudice against their own species pretty quickly.
As pointed out on the YMMV page, the flood Darla caused could have injured or killed several people, not to mention the damage costs to the studio.
Maybe that's how she lost her money as well as her career. Perhaps she was forced to pay for the damage?
Before the ivory trade was banned, piano keys were made from elephant ivory. When Woolly plays the piano, he's pressing keys made from dead elephant tusks. (Or maybe in this universe, the poorest elephants are reduced to cutting their own tusks and selling them to survive.)
What'll happen to Max once the Darla hot air balloon completely deflates? Will he fall to his death? (Although… probably not. He seems pretty durable.)
It's all well and good that animals were able to break into larger film roles after the success of the show in the finale, but... The posters only show the animals who participated in that event. Were they the only ones who were memorable enough to make an impact on filmgoers' minds?note Most likely, they had the "star power" to immediately get top billing, plus they had been around for a while. So of course they would get the headline posters in the first bit of time. But still. Food for thought.
If the film takes place in 1939, how did the animals live long enough to star in (at the time) recent movies like Grumpy Old Men and Twister? Especially Cranston, Francis and Woolly, who are already pretty far along in years.
This can become Fridge Brilliance if you remember that this movie shows the acting minority becoming accepted much sooner than real-life minority actors were. This could conceivably have led to cinematrogaphy moving faster than in our world, and thus to the counterparts of some movies being made much sooner.
Okay, so Danny ruins the Little Boat on the Sea number by over-embellishing his simple "meow" line. Darla calls for Max, who says "How does the kitty cat go?" to Danny...except Max wasn't even in the building to see the ruined take. Darla just angrily points at Danny when Max arrives, so Max would have had no idea what Danny did wrong; he asks his question as if he saw the whole thing.
1) Max, as Darla's butler, would be a good person to practice with for her lines and as such would probably know a good portion of the script.
2) Racism, or specisim in this case. Danny's line for any movie would probably be some variation of "meow."