You don’t have to do it the traditional screenshot way.
1) Using the developer tool
1a. Open the photo you want to save on your browser
As long as you see the picture standing by itself, you’re fine. You could open it from a person’s profile, from your feed, or from explore feed, etc.
1b. Open the Developer Tools
Right click on the picture and select Inspect. You’ll see a rectangular window pops up at the bottom of the screen. That’s the Developer Tools and with a line of code highlighted.
1c. Hide the code element being selected
Right click the line of code that’s being selected and click on Hide element.
1d. Right click save-as
Now you can save the picture in a regular way. Just right click on the picture and select Save image as!
2) Using Snip & Sketch tools
If you decide to try this, I have to warn you that your final picture will have the arrows and dots if the post contains multiple picture, since those features cannot be hidden automatically.
Open the picture that you want to save
If the picture is bigger than your screen, do this:
Select the 3 dots on the right hand corner of the browser and click on the minus button to zoom out your screen until you can see the entire picture.
Screenshot the picture using Snip & Sketch
Press Windows + Shift + S
Or search up Snipping Tools then click on New to take a screenshot of just the picture.