Verse and reverse

In Competition No. 3098 you were invited to submit a poem that can be read forwards and backwards, i.e. from the top down and the bottom up.
 
I worried, as the entries trickled in, that I had set the bar too high, especially given the anguished comments that accompanied some of them. ‘This was one of your really tough assignments,’ wrote one old hand, ‘a combination of mathematics and poetics.’ ‘This challenge almost made me cry,’ wailed another.
 
But I needn’t have worried. Your submissions — some palindromic — combined technical adroitness with clever content. High fives to the winners below who are rewarded with £20 each.

This is a verse you can flip, you can flop.
The top is the bottom, the bottom the top.
It works up or down. It’s just like a stairwell.
Aloha. Shalom. It’s both greeting and farewell.
It doesn’t much matter. It’s fine either way.
Does day follow night, or does night follow day?
Was it the chicken or egg that came first?
Whichever you choose works as well when reversed.