The Warp Transform tool can shape things. Before Gimp version 2.10 it was called iWarp and was in the Filters tab (near the top of the window) under Distorts and worked a little differently. You can use it to move pixels, grow an area, shrink an area, swirl parts of the image, and a few more things (in Gimp 2.10 or greater the place you change those settings is right above where you`d change the size of your brush).
You`d probably want to scale up the image before using the tool, though. You can scale it using the scale tool.
If the dotted yellow border that`s visible on the picture you posted cuts anything off then you can click on the layer it`s on then go to Layer (near the top of the window) and click on Layer to Image Size and it`ll stop cutting things off.
If you select something you can move it by holding down shift-ctrl-alt then hold down left-click and drag it around (only let go of shift-ctrl-alt when you`re done moving it).