Birds aren't real.
The selection of people is also quite poor but that's because people are a poor choice: Most notable historical people are very linked to specific countries, often against other countries so picking neutral ones is hard. They also clearly decided to have an equal number of men and women, which makes it even harder. Obviously there aren't enough different banknotes to represent every country, either.
Faces are a terrible idea for a common currency shared by 21 countries.
You have to pick one writer, good that the English left for good so Shakespeare's out, but how do the French feel about Cervantes vs. Victor Hugo?
The Poles complaining that they didn't get enough recognition because Marie Curie's maiden name isn't given enough prominence should tell you all there is to know about this being a good idea.
I don't think anybody would mind since there's already Marie Curie, which is an obvious choice because she's both Polish and French. I don't know how the Polish take it but the French have no particular feelings about her being Polish as well.
But why are a Greek-American, and an - unknown to the majority of Europeans - Austrian in there?
How many counties more populous than Austria are unrepresented? Do all EU countries count, or just EZ? (Poland is not EZ, is represented, still complained)
It's an impossible list. Europeans don't necessarily have shared heroes, and if they did, some of these wouldn't be top 6.
As for the smaller countries- well let's face it do you think anyone in Europe gives a shit about Dutch or Estonian history and culture? Its France and Germany all the way down I'm afraid. At least we still have the veto.
And no one gives a shit about the (18 million) Dutch, but we picked Bertha von Suttner.