Continuity mistake: When Sammy first offers the drink to Diana (in a close up), Diana takes the mug in her left hand. Just before the camera switches to a long shot, Diana switches the mug to her right hand. In the long shot, Diana still has the mug in her left hand and she sets it on the wall to her left. The camera switches back to a close up and Diana again has the mug in her right hand. When Steve asks her to dance, Diana again sets the mug down on the wall, this time to her right.
Revealing mistake: When Diana and Steve sail from Themyscira to London, the sails on the boat just hang there, indicating that there is no wind. Sailboats need wind to move and the sails need periodic adjustment depending on from which direction the wind is coming.
Continuity mistake: Wonder Woman is fighting the soldiers on the second floor in the village, after she retrieves her shield. Her sword goes from properly in her hand, to being held by the blade, to held by the blade upside down, but when she looks up, just before going through the window, the blade is normal again.