The rich learning resources and contexts learners experience in their everyday life could play important roles in complementing formal learning, but are often neglected by learners and teachers. In this paper, we present an intervention study in "Move, Idioms!", a mobile-assisted Chinese language learning approach that emphasizes contextualized learner content creation and meaning (sense) making with their daily encounters. In the study, students used smart phones on a 1:1 basis to take photos of the real-life contexts pertaining to Chinese idioms or conjunctions, made sentences with the idioms/conjunctions, and then posted them onto a wiki space for peer reviews. This paper focuses on analysing students' on-campus face-to-face collaborative learning process. Inspired by the notions of mediation by artefacts and distributed cognition, we derived a novel visualization approach for descriptive analysis of the small-group activities to provide a synoptic view of the process of student artefact co-creation in such collaborative activities. Through our artefact-oriented analysis, we foreground the significance and the potential impact in fostering learners' habit of mind and skills in identifying and appropriating "in situ" resources to mediate their learning activities in any learning space, rather than always being "dictated" by the resources that the teacher provides with fixed roles to play. (Contains 1 table and 5 figures.)