The image you use in your Facebook Ad is the most important part of your Ad.

It has one job:

To grab people’s attention.

Your copy is there to sell what you’re selling- the image is there to stop people scrolling.

What else could help?

Colour- including your border and background.

No text- if your ad has too much text then facebook will show it to fewer people.

Not boring- not let your customers scroll past you.