The scan lines are pretty clear… Generally you want the scan lines to just touch.
Lightburn, set to the same setting should do the same job… There isn’t anything special that Lightburn does what you tell it, run at a certain speed and adjust power as specified. It’s hard to understand that the speed/power on one is not the same as the other.
Something is different…
This is a very good video on photograph reproduction that explains most of the issues. Works for any laser…
If you want a lighter colored engraving, you may just want to change the speed/power settings. There are lots of settings and I can’t tell you which ones may be right without knowing current settings, seeing a picture of what you feel is wrong and knowing which way you would like to go with your work.
If you want a darker image and more contrast, treating the board with a baking soda and water solution can help that. It will however make it a necessity to start again with speed and power settings because it’s very effective at darkening the dark parts without removing much material.