Drumlins are streamlined mounds of till that are associated with glacial flow, and form at the base of moving glacier sheets. The long axis of these features are usually parallel with this flow, and the steep end (stoss end) faces the direction from which the glacier advanced. As observed in the photo, the glacier moved from right to left. Drumlins may rise to elevations exceeding 30 m, and extend to lengths of 800 m.
If you look at Drumlin Co-op's site as a whole, it is of an oblong, teardrop-like shape and is situated upon a mound, thus the connection to the word "drumlin".
For more information about drumlins and other landforms, please click here.