Actually void* just points to anything, with no regard to the type of that thing. Pointing to the void is more accurately described by NULL pointer.

Swiping left/right to seek only works if the video is paused apparently

Looks like you need to insert the raw image link, not Reddit's media wrapper link.

Hmm let me try:

reddit image linking is broken?

Well you didn't link to a reddit image, you linked to Google image search result page which is not an image.

Still false, thanks to compiler optimizations. Remember that integer overflow is UB. (unless you're using unsigned int or a programming language which strictly defines integer overflow, possibly as an error)

P.S.: Assuming this is C/C++

But that often leaves behind the registry entries which may or may not cause problems.