Hmm.. I stand corrected. "maxes" does not show up on the Scrabble word verification page but seems to show up in Dictionary.com and plays ok in Words With Friends
I can see how this is possible except for the word "maxes" is not a valid word, so this can't be a valid screen shot. However you don't need the word "maxes" to make this work. You could have left the "m" off and just gone with "axes"