Here are some ideas, let me know what you think, if you hate it be honest, I can make more if you want.

https://steemit.com/minnowsupport/@swerdan/my-welcoming-images-design-contest-ideas

I think this one has a nice pun with picture:

This is the flavor text they used:

I think this one can also work because it plays in to the upvoting what you want to see in the future:

The background images are both mine so they can be used for what you guys need it to be used for.