Prepare 1 set of cards per team member. A set of cards contains 1 elephant card, 1 boot card, 1 happy sun card, and 1 moon card. Explain how they each choose one card from their set:
If a team member thinks there is at least one 'Elephant in the room' (unspoken but important problem) for this team, then choose the Elephant card. Choosing this card doesn't mean that they have to talk about the Elephant or even say what they think the problem is.
If there are no Elephants, but they got their feelings hurt in an interaction at least once since the last retrospective (and didn't mention it), choose the Boot crushing flower card.
If everything is hunky dory for them, choose the Happy Sun.
If they're uncomfortable sharing, or don't feel like any other card fits, choose the neutral Moon.
To preserve anonymity, everyone places their chosen card face down on the feedback pile and the rest of their sets face down on a discard pile. Shuffle the discard pile to ensure anonymity and put it aside. Shuffle the feedback pile and then reveal the cards one at a time.
If your team has 1 or more Elephants in the room, you have some serious issues with psychological safety. Let the team sit with their new knowledge and offer a larger retrospective soon to make space for them to share if they wish, but do not ask directly who chose what. Preserve the anonymity and do not coerce explanations of the chosen card! This is a critical opportunity to build trust and preserve your ability to gain insight into the state of the team.
In the same way, depending on the size of your team, two or more hurt feelings suggest that you may have safety issues. Two or more Moons also suggests a lack of psychological safety. Take this feedback into consideration when designing your next retro. There are lots of great ways to more thoroughly dive into and surface learnings, this activity just points out when such a retrospective is needed.