The appearance of Leonardo's turtle com changes up close as he's talking to April on his turtle com outside the channel 6 building.
When the turtles are eating their pizza, there are pepperonis on the pizza instead of anchovies.
When the waitress at the pizza parlor brings the turtles their pizza, there's only two anchovies shown, but after she sets it down on the table, there are more anchovies.
When April is talking to Leonardo over the turtle com, she is shown holding her turtle com on Leonardo's screen instead of looking directly at him.