Hemingway got away with short sentences and sometimes they are the best option.  When are they not the best option?  I find if you have opened a scene up and you were descriptive to begin with you can get away with shorter sentences that follow.  Some descriptions though, drag on and on!  Don’t be a dragger!  Say what you need to say and move on.  Kind of like shopping in Walmart- make a list then get in and out!  Otherwise, when you are at the checkout and she gives you a total of seventy-plus dollars you think to yourself, ‘What did I buy!’   This is the same with sentence structure– Drop your description or the point you are trying to make and don’t dilly~dally!