Here's the Final Art High Res.
having trouble retrieving the drawing. . which looks good. . .
besides what Rod says. . I would also include that whales are streamline. . so there is no visible genitalia while swimming, unless maybe its a nursing mom with mammary glands. . it's all inside while male belugas are swimming. Can't find any good picts on line. . so I know what I will be doing during the next stranding. . taking ventral pictures.
The mellon is the forehead part, the beak would correspond to lips. Maybe reducing the indentation between is what is needed. the Axial girth refers to B but the girth at both A and B could be increased so that the long taper into the neck is shortened and there is a steeper dropoff from the girth at A to the neck. Older larger beluga will often have wrinkles at that point because the neck is rather articulated while the body is more ridged. I don't have so much experience with young animals.
Looks young like a 2 or 3 year old. The beak looks a bit too prominent and the axial girth (at the flippers) looks small. Also when you zoom in there is a net like pattern on the skin.
Here's a version with a blue background
Here's Jack's first draft. (72dpi)