Is it possible to edit a Photoshop mockup file in Gimp on a Macbook?

[Lognill]

I'm new to Gimp. Is it possible to edit a Photoshop mockup file in Gimp on a Macbook? In Photoshop, I was able to just double click the "Edit Me" section/thumbnail and a new tab would open where I can place my design, but I can't do the same in Gimp. I want to attach a screenshot to give an example, but I couldn't due to the file being too large. Watching videos to help me reduce the screenshot file was no help either.