Sometimes when I make an image larger or smaller the Effective PPI data on the Information pane changes into a format that I don't know how to read.
I'm attaching an example for visual reference, but usually my image will be 300ppi and when I modify the size the Effective PPI will turn into something like 452ppi. Sometimes however it'll be 291x284.
What does that even mean?
It's out of proportion. The width is 291ppi and the height is 284ppi. If you're holding Command and dragging a corner to change the size, include the Shift key to keep it proportional.
Migintosh: That's it! Now it makes sense, thank you.