If you show the learners the curiosity line of the AACU intercultural competence rubric (or the communication line thereof), you will deepen their engagement with this exercise as a learning opportunity.  To turn the learning outcome(s) towards self-awareness, you'd want to include some work on their own cultural values, and open discussion on how their values shaped their picture choices and captions. Try HubICL tool #384  (Culture and Values) or #363 (Mapping my cultural values)  .  Emojis & Culture (#572)  is another one that will spark good discussions about visual communication & cultures.