A question about the display of images in Writer.

I have a question about the display of images. If I insert an image which has words (like a graph with labels), the letters are broken up and difficult to read. This doesn’t happen if I insert the same image into Word or in Apple Pages. It’s not a huge issue because if I save the document as a docx file or as a PDF, the letters are clear. It seems to be the way the image is displayed in LibreOffice Writer.

I’m using LibreOffice on a MacBook Pro with Retina Display.

Is there anything I can do about it?

What"s the image format? JPEG, PNG, TIFF, BMP, other?