The practice of "flexing," showing off one's wealth and status, gradually penetrates daily life on various social media platforms, most notably Instagram. We investigated the extent to which exposure to conspicuous consumption by a stranger stimulated the viewers' materialistic aspiration and whether this effect could be mediated by anticipated engagement and moderated by trait mindfulness. A large number of Instagram users in Indonesia (N = 2,296, 75.30% female; Mage = 31.14 years old, SDage = 7.09) completed the trait mindfulness scale, randomly received a single Instagram photo showcasing luxury material vs. experiential purchase, provided an estimate of the intensity of love and comment from other viewers (i.e., anticipated engagement), and filled out the materialistic aspiration scale. Participants exposed to material purchase reported higher aspiration than those exposed to experiential purchase, but lower anticipated engagements also reduced materialistic aspiration. Participants with higher trait mindfulness were better at distinguishing the effects of conspicuous consumption on anticipated engagement and materialistic aspiration. These findings indicate that the viewers' anticipation of collective attention could reverse the impact of exposure to conspicuous consumption and the potential of trait mindfulness as an anti-mimetic quality for situational materialism.