Dark patterns FTW?
The problem with moving things around on hover is that the targets jump. This isn't really a problem for the item being expanded. As Jamezrp pointed out, that may be intentional. Maybe Netflix is using a dark pattern to try to increase engagement. I say dark because it's not an ideal interaction, but Netflix may have found the "negative" side effect to work in their or their users' favor.
Rule of thumb
In general, you don't want to do this kind of expansion because it creates a certain amount of disorientation. If the thing being expanded (intentionally or not) is just one option among many in the user's consideration set, then they'll have to stumble a bit if they decide to try another option before committing to the click.
A better option
If you're tempted to use a hover pattern (or it's tap equivalent in a touch UI) to provide expanded info, there is a better way. Rather than distorting the whole environment, just change the state of the item in question. In the Netflix example, the additional info could simply be layered over the cover image without any expansion. The cover attracted attention and now it becomes simply a backdrop.
So this ...
Becomes this ...