You are doing a lot better with images than I have ever been able to. Keep improving until you are happy with it 
If I remember correctly you have PhotoShop. I may have suggested this method to you earlier… If you are starting with a color photograph or better yet a Water Color rendition of image this will get you best results with one caveat, all lasers are not engraving exactly the same so you may have to adjust speed as well as power.
With PhotoShop:
Go into “image” - “Adjustments”, “Black and White”, “Adjustments”, “Shadows and Highlights”. They will be set on an average setting, leave it that way. Save as .png
Drop the image into Lightburn. Again, I think you have a CO2 Laser 50 or 60 watt.
Set speed at 265, power at 25% for light engrave, 35% for a little darker.
What is the min/max power both 25?
I have been setting minimum power to 4 and Max to 45 with speed at 225 lately. You will need to play with the max and the speed for your machine