It always looks so silly to me when people use these weird frames. It's obviously a stock photo and it's just distracting, just show me the damn screenshot.
Your imagination and abstractive abilities let you see a screen capture and put it in context of your device usage. Others can't - they need the device scenery to make it real to them.
I don't know why I'd be the only one. How t already (very likely) using the device you'd use the software on, in the environment you'd use the software in.
Why would you need to see a device you don't have in a generic setting you might never be in, perhaps even with a person that isn't you? How does this help the imagination?