If you’re going to display pixels on the user’s screen, you have to send those pixels to the user. Magic still doesn’t exist. HTML img tags are indeed a “pointer,” but once the user’s browser has the path to that image file it will download the entire thing.
That said, there’s no reason to send an image that’s any bigger than it needs to be. Sending a scaled down thumbnail if you know it will be displayed small is sensible. Sending the entire 1200px wide or whatever image it is and just squashing it into a 100px wide box in the user’s browser is not.
If you’re going to display pixels on the user’s screen, you have to send those pixels to the user. Magic still doesn’t exist. HTML img tags are indeed a “pointer,” but once the user’s browser has the path to that image file it will download the entire thing.
That said, there’s no reason to send an image that’s any bigger than it needs to be. Sending a scaled down thumbnail if you know it will be displayed small is sensible. Sending the entire 1200px wide or whatever image it is and just squashing it into a 100px wide box in the user’s browser is not.