Why I can't add an image from my computer to html file in text editor

html
#1 

<!DOCTYPE html>
<html>
<head>
	<title>image</title>
</head>

<body>
	<img src="london-girl.jpg" alt="London" />
</body>
</html>
#2

This should work if your image and Index.html are in the same folder and the image name is exactly the same as you've typed it in the HTML are they?

#3

it is in the same folder with the same names - just doesn't work as well as href links and even .css files when trying to do some styling.
But html it self (including styling without css) works. My editor is Sublime text. But I have instaled and visual studio code editor for python in mac and after I saving css file it saves as visual code file. Maybe there is a interaction between editors?

#4

correct extension ? its a jpg not a png ?

#5

Yes it was jpg definitely. I still can't upload images from my computer - doesn't show anything on page, have tried countless jpg images, but finally managed to put an image from internet. And css works now. Didn't understand links between .css file name and its link in html.