Attractive though the addition of a duck is, I am not in favour of this proposal. However, I am not opposed on the grounds that it is 'too silly'. I am opposed on the grounds that it would institutionalise what is essentially an 'in joke' and thereby symbolise a kind of exclusivity which I would not like to see the site embrace.
I realise that, in practice, people are unlikely to even notice the duck. However, I think that the image is a statement about the community and this community's attitude to visitors, including both regular members, newbies and passers-by.
I may not be explaining this objection very well and I do not expect this post to be popular. I post it because, after considerable thought, I concluded that somebody should say it. Unfortunately, nobody else has stepped up, so the somebody happens to be me.