Time is a slippery thing. In comics we, the creator, have the option to present time in any number of ways. We can use ellipses to skip over seconds, minutes, days and years. We can make use of a variety of different panel transitions to hop across time, to intercut between scenes, and to present moments as hour, or hours as moments. Some scenes need to be fleshed out more than considered in the script, as in the drawing it becomes clear that certain gestures require a number of panels to illustrate properly.
The montage, then, takes a number of different scenes and stacks them side by side, showing only the bare minimum of each in order for the reader to make sense of what’s presented. In this example the reader is asked to see the naked butt, the easels, and the paper on the floor, and understand this is a life drawing class. It is quickly followed by a seperate scene of physical training, with no navigational cue that the scene, time and place has changed. The overarching idea that connects these disparate scenes is that the protagonist is applying himself and working hard at his pursuits. Like Rocky, if he went to art school.