I'm fairly sure the various "mouse pad" creations shown are inserted by whomever made the video and not from the episode itself. In the episode itself I'm fairly sure Data creates odd clay creations. (As the others in the class are also working with clay.)
In fact, checking the episode, Data first makes a sculpture of a PADD (remarking that it's accuracy is within 1% or so which seems oddly inaccurate for Data) and Troi says it's not abstract enough and tells Data to sculpt "music"; Data takes some confusion, wondering how he can "sculpt sound", but finally messes with the clay making.... A clef. Troi tells Data it's a "start" before being paged to the bridge.
And, yes, the scene is from "Masks."
