You can move the loupe anywhere you want. Also, you can hide the magnifier loupe by clicking the 'switch' button (placed in the bottom of the image).

You have the possibility to zoom in the spectrum by selecting a spectral region you need to be increased (along axis x); to zoom keep the left mouse-click continously pressed, drag (to left or to right) and release the left button. To return to the initial size spectrum, press the right click on the spectrum -> Zoom -> Reset View.