I'm sorry if this sounds like I'm being pedantic, but that is a URL for a webpage
I've attached a screenshot of what that URL actually returns
Even without looking at specifically what the URL returns, the fact that you see a file name at the top of the page, with Google's mountain-ranges icon for an image, and an "Open with" dynamic menu, etc. all point at the fact that this is a webpage (that contains an image), and not an image.
To illustrate with an example of one of my images, it's the difference between using:
or
or
I'm not saying it's unreasonable for you to expect me to have implemented something that is capable of parsing HTML, reading through a webpage looking for <img> tags, getting the src from that img tag and then fetching that image. (Although in this particular case, it looks like it'd be more complex as the HTML in the Google Drive page appears to be obscuring the image location behind some dynamic scripts - it's not actually in the returned page HTML, perhaps as a mechanism to prevent people using Google Drive as a free image hosting for webpages)
I'm just saying that I've not implemented anything like that. What I've got now just needs the location of an image.
Normally what students would do would drag an image to the textbox directly, or right-click on an image and use the "Copy image address" menu to get the URL to use. With most sites, either of those work fine. But Google Drive seem to have blocked both of those - again, presumably in an attempt to prevent people using Google Drive as an image host.
Kind regards
D