As part of a learner's learning ecology, the informal, out-of-school settings offer virtually boundless opportunities to advance one's learning. This paper reports on "Move, Idioms!", a design for Mobile-Assisted Language Learning experience that accentuates learners' habit of mind and skills in making meaning with their daily encounters, and associating those with the language knowledge learned in formal learning settings. The students used smartphones on a 1:1, 24x7 basis to capture photos in real-life contexts as artifacts related to Chinese idioms, made sentences with the idioms, and then posted them onto a wiki space for peer reviews. In this paper, we focus on investigating students' cognitive processes and patterns in artifact creations in informal settings. Our analysis and interpretation of such student activities is framed by the notion of Learner-Generated Context (LGC) (Luckin, 2008), a reconceptualization of "learning contexts" that implies greater learner autonomy. Through two case studies, we gained better understanding in the impact of LGC and how it is crystallized in seamless learning processes with the interplay of physical settings, parental involvements and the mediation of mobile technology.