Why doesn't my homepage image recognise safari window size until I resize it?

Hi there,

I am doing a Tesseract walkthrough tutorial. Everything works fine, but the homepage image doesn’t automatically snap to the right size until I resize the Safari window. In Goggle Chrome it seems to load fine. Any ideas? I’m using the visual editor plugin also.

I have uploaded a couple of jpegs showing the before and after I resize the safari window.

Before I resize the window: https://imgur.com/Jr6t1mZ Notice the white margins to the left and right.

After I resize the window: https://imgur.com/lBKEM8s Notice the image has now recognised the appropriate window size and snapped into place.

Thanks for any help in advance.