A sketch takes longer than 5 minutes. One time I went to Disney and there were professional artists (And I mean professional artists who can draw Disney characters identical to their original sketches from original artists) and it definetly takes them more than 5 minutes to sketch a full body character. I know, I watched one of them draw Donald Duck in full body and detail, I went around looking the store and when I came back about 10 minutes or so later the artist was still drawing on the same character, finishing up the legs and starting with the background. 5 minutes is enough to get a character face done in good detail, but it definetly takes longer then that to draw up that DVD cover even in simple sketch.
Universal's coloring and shading programs aren't as better as the one we can obtain like Photoshop CS2, Paint Shop Pro, you name it. These programs are extremely expensive for a reason. You can find them but it'll be tough to buy them due to their high price. So if an artist can draw a great picture and color it like this DVD cover in about a week with these kind of high quality programs, what makes Universal different that would take even less time than this to make their pictures and covers?
A possibility of a picture like this taking little time to create would be a team of about 10 people sketching respective parts of the cover and then stacking them in frames for the final piece, but even then they would have to scan it all together and then color it. By then those 5 minutes would've been long gone.