Techno-Orange Theme header – help!

I’ve been trying to implement our logo into the header img. I’m got the jpeg image edited but when I change the image location in the css, it doesn’t show properly when I reload the page.

Since the images are exactly the same and I’ve simply removed the speech bubble and placed in the new logo, I’m stumped as to what is causing the problem.

I don’t have a whole great deal of experience with coding – that might be a start!

If you could give some tips, that would be much appreciated.

Many thanks!