That was my original impression when I saw the image (and I posted to this effect when I first saw a picture of this steelbook) - "WTF is a hand doing on the cover" was my immediate reaction?
Then I saw the original film poster kindly provided by
@Steelselecta and I thought if this was deemed good enough for a movie poster then it's good enough for the front of this steelbook . . .
Regarding the other original poster kindly provided by @C.C.95 I would say that this image is too 'strong' for the cover and could alienate some prospective purchasers, though of course others may be alienated because they are angry that a severed hand image was used when there is no severed hand in the film blah . . . blah . . . blah . . .
Because the foot image from this poster is maybe too strong an image for the front of the steelbook then the half leg image from the Blu-ray cover is no less ridiculous than the forearm as to my knowledge the severing was at the ankle and no higher . . .
I prefer the image central like this one and not creeping to the edge like that on the DVD or Blu-ray covers seen above and I prefer to see the part where the limb is severed than have it disappear out of picture and I'd rather see the blood than have the image sanitized and any blood or sign of severing removed.
In conclusion: IMHO this is a good image - not too strong but strong enough - and If this steelbook is a shade of white (NOT ANOTHER SILVER STEELBOOK, PLEASE) with the type of quality gloss finish that we have come to expect recently from EIV and EMBOSSED FILM TITLE AND BLOOD then I think this will look pretty damn good and I'll be forced to shelve my original feeling of disappointment when I first saw the picture..