This must have been an annus horribilis for Laura Mosquera, so forlorn and melancholic are the images in her exhibition, called “in the deep end.” Best known for large and sometimes ebullient paintings of young men and women posed against sharply defined abstract backgrounds, the artist here showed only a single painting. Eleven mostly small drawings made up the rest of the show, suggesting that, for Mosquera, hunkering down over a small piece of paper, using colored pencil or graphite, working with knuckles and wrist rather than elbow and shoulder, is more in keeping with her mood than painterly