Are you intending to dive with them in bare feet?
Your heels are supposed to hang over the edge on open heel fins.
Those look too big, to me (presuming you're planning to wear them in bare feet. It looks like there is a gap on the sides of your foot. But, a neoprene sock or bootie might totally fix that. And the picture could be totally deceiving me.
I'm not sure why so many people try on fins and their toes touch the end of the foot pocket (or stick out) and they think that means the fin is too small. If it's too small, you would not be able to slide your foot into the foot pocket that far. You wouldn't be able to to slide it on very far at all.
If you put shoes on and your foot went in easily without touching the sides of the shoe and then slid way forward until your toes hit the end of the foot pocket, would you say they were too small?