My gums don't show when I smile, what can be done? (Photo)

issue is not with gums. gummy smile does not looks good. issue is with buccal corridors [dark areas on both side of teeth]. best option in yr case is expansion of arch. demon braces or aligners are good option for u. 

It's a limited photo but most likely you would need to have jaw surgery and bring both upper and lower jaws forward.  

On your photo you show at least 2/3 of the teeth. You do not show the back teeth as much and this could be due to a narrow arch smile.Your upper teeth show is perfectly acceptable and I would not worry about it. This is usually something due to the vertical height of your upper jaw which should not be played with.In terms of improving your smile, you could you use Invisalign to straighten the upper and lower teeth and also widen the smile.