Background: Makerspaces are proliferating U.S. public schools and libraries. Few studies, however, take an "in situ" view on the pedagogical moves of mentors, and fewer still engage with ideologies of race and class therein. Without this, principles of pedagogy or design that build toward expansive learning for racially minoritized youth will remain elusive. Methods: Semi-structured interviews and fieldnotes of mentors in a U.S. public library makerspace were taken over six weeks (n = 12). The mentors were predominantly white and all were professional artists/creatives; teen patrons were predominantly racially minoritized. Findings: Three recurring pedagogical moves surfaced through the interplay of prolepsis and telos as an interpretive lens. We identify how mentor history/memory and future imaginings of youth as adult creatives--both of which intersect with ideologies of race and class--shape their mediation of learning. Contributions: (1) Documentation of specific pedagogical moves that extend efforts to name the work of mentors; (2) Presentation of prolepsis and telos as a lens to recover the power of imagination in pedagogy; and (3) Extension of how prolepsis is used to the study human learning and development by bringing it in contact with the study of ideologies among educators.