When having a picture framed it is worth discussing the final layout of the frame and how the overall look of the picture can be enhanced by some simple design adjustments.
Consider the three images below. The first shows a perfectly good frame with a mount cut equal size all around the image. The blue double mount enhances the colour of the kingfisher. The square format is not uncommon but, to my mind at least, the picture is saying ‘could have tried harder’.
The second image has had the mount extended slightly at the bottom i.e. the mount has been ‘weighted’. This is a common approach and is often used to overcome a visual illusion that can cause some images to appear to have a narrower mount margin at the bottom. There is also a view that this slight weighting approach dates back to the days when pictures were hung from wires and picture rails.
The third image has had the mount weighted by adding a significant margin to the bottom. This allows a rectangular frame to be made which can be visually more pleasing and I think the additional space around the image gives a more harmonious look to the finished frame.
At the end of the day it is down to personal a taste and preference however a visit to a bespoke framer will allow you to make the right choices guided by their advice and experience.