I see the round 2's have begun to hit the mail service!
FWIW everyone worries about how the originator will like the work done, and how the next quilter will handle what you did! But the whole fun of a Round Robin is the unexpected. In one RR I participated in, the only prompt was "Make it even better!", and that was a lot of fun.
When I get a RR to work on I have found a few things that help frame my thinking about how to approach that next round (apart from any prompt given):
1. Play with scale
2. Which colour in the piece has been under-used and how can I either add more or emphasize what is there?
3. Can I push the composition off centre? (that usually adds interest)
4. If there is a lot of linear, straight line components, can I add curves/circles? or vice versa
Oh and one tip for photographing: stand close enough to your finished round such that the piece fills the frame. That will look great in the final slide show.