How do I maintain image position depending on screen resolution?

Hello! I’m working on a personal webpage and have several images that shift around when the screen size changes. When I change the resolution to, let’s say, 1600, the objects in the room begin to float about like so:

How do I ensure that the images stay stagnant, i.e., in their correct position relative to the room layout I have designed? (N.B. The black-and-white image of the room is also an image, not a background image, in case that helps.) I’ve tried stacking the images and meddling with the “size,” “position,” and “adjust” interfaces without success.

Let me know if you can help, and thank you for your time!