I have researched the list of existing Companion modules and requests and have determined this has not yet been requested
Search for Image from URL yielded no results
The name of the device, hardware, or software you would like to control: Generic HTTP Module
What you would like to be able to make it do from Companion: Currently the Image from URL Poll Interval is either 0 for disabled or some number of milliseconds. There is no way to assign a custom variable to that Poll Interval. Either a Manual Pulse or Custom Variable assigned to the poll interval would alleviate the constant streaming of thumbnails and allow them to only be pulled on an update flag.
Direct links or attachments to the ethernet control protocol or API: Native Companion Generic HTTP Module