Antony has changed by becoming more powerful and is taking more control over Lepidus “his corporal motion govern’d by my spirit.” Implying that Lepidus is under Antony’s fumb. Another quote to back up my answer ” This is a slight, unmeritable man, meet to be sent on errands; is it fit, The three fold world divided, he should stand One of the three to share it ?”  Here in this peice of text he is questioning wether Lepidus is werthy to be one of the 3 that are in power as he is met by being set on errands.

This is why I believe that Antony has changed to be in more control of Lepidus because he doesn’t seem to like him and don’t want him to be one of the 3 that has power over Rome. Antony also seems to enjoy having Lepidus run errands and having him under his fumb.