Does anything happen when you try to press it?
Maybe they updated it, but I don’t have plus anymore so can’t check! It did look like an area you could tap to change when it first launched though.
ETA: screenshot here of what it used to look like at launch.
And here’s how it looks on my brother’s app now:
So they have made some tweaks! Tweaks that very much do suggest to me that you’ll be able change the source in a future update! Can’t wait!
This would be a wonderful improvement too. I did like the graphic in the feed too though! Can’t put my finger exactly on why I liked the virtual card graphic but could never stand the round up one nor the thank you emojis.