Thanks for your comment!
No, I do not ever show pictures of the dogs. Although, I just realized that the write-up does not make that clear. I will update it.
It works better when voters are just giving their best guess at the relative size based on their current knowledge. This makes it easier to correlate to software features. I also like it when I get people voting on the poodle based on their initial assumptions (toy vs. standard). The votes expose the assumptions, so we clarify and re-vote. Having pictures of the poodle would make it harder to expose this.
With lesser known dogs, like the Newfoundland, some voters will actually google the dog in order to show others what it looks like before the re-vote. Again, a picture would prevent this.

I totally agree that relative sizing should be a learning point. I don’t know why I missed it. I’ll update that too!

Thanks for the great feedback Russell!

Don

- Do you need to show actual pictures of the dogs or do you just need story cards with the dogs names?
- I guess another learning point is that the game emphasises the relative size aspect of story points

Thanks for making this resource available.

Kind Regards

Russell