From that model, I removed the text
(I will upload a customizable version asap)

This is designed to fit a standard tealight inside.
And 4 lithophanes with the size of 45-45-3.2 mm

I made the negative cone shapes bigger so they now sould fit perfectly on top.

You can make your own lithophane with your custom picture or whatev.
From this site: https://3dp.rocks/lithophane/
-(If you are not sure about how to use it, notes below!)-

stick to these parameters for the pictures:
45-45mm-3.2mm (maximum)
otherwise it won't fit the box and, or would not align with it's shape.

With these dimensions.
The clearance should be just enough for handling some unplanned inperfections.
(such as elephant footprint or some ghosting)
And of course, the candle won't melt away your print :)
But keep in mind, that you shouldn't use a candle with an excentered wick. I made the box's wals just far enough from the expected flame.

Notes:

(Don't remove the candle's tin cup it's easier to remove the used candle since you can't just melt out the wax. )

Using the web litophane generator:
-First click the images menu on top.

Upload your image (prepare it to be squared!)
-Head back to Model menu on top.
Check the model it generated. Mainly it's shape is what's important rn.
-Head to Settings menu -there Model settings
-Please be awere of, that site is a bit sensitive, you need to write the two numbers than insert the dot between them :)

-Change the values to these :
Maximum size-- 45
Thickness ------- 3.2(multiplied nozzle diameter but maximum 4mm)
Border ----------- 2.4 -(anything betveen 0 - 2.4)
Thinnest layer---1.2 -(that's gonna be the lightest color on the image 1.2 mm minimum)
Vectors per pixel - Bump that up to 8 so the tiny image gonna be nice and detailed.
Base depth------ 0
*Curve------------- 0 (you don't need that for that candle box)
Also feel free to play around and explore that cool feature

-Got to Settings-- Image settings

Set the slider to positive image ! You don't have to change anything else.
Go back to model menu and click refresh to see, if there's anything out of expected.
than download your lithophane model.
Print it vertical, so it will have more details
use the raft adhesion for the pictures

Thanks for visiting my first share.
Have a nice day and never stop beeing creative!