Since that first example image has a transparent background, we can safely say that it was brushed using the Brush tool.
To make things easier, I would perhaps use Dodge tool and Burn tool.
Some key points ( specifically for creating this type of shape ):
- First I made the 2 base shapes on separate layers.

Then I laid down some basic lighting to make the corners pop out a bit.
- First few things about the Dodge tool.
- You can switch to the Burn tool on the fly by holding down the
alt
key.
- If you right click while holding down
Shift
, you can change the Range easily.
- Speaking of shift, Pretty much for everything, except for the diagonal lines, I'd hold down
Shift
to make sure the lines are straight.
- You'll probably want to stick to Ranges: Midtones and Highlights.
- If you use
Highlights
, it will add a little bit of a tint based on the color below. If you use Midtones
, the color will be more dull.
- To get similar tint as in your example image, you'd have to mostly do it with
Midtones
and then switch to Highlights
at the end for a few strokes.
- Also, using a mouse, I'd probably never raise the Exposure of Dodge tool and Burn tool past 25%. When I made this example ( with a mouse ) I kept my Exposure between 5-20%.
- Use "Soft Round Brush" = Round brush with 0 Hardness.
- In this step the brush size should be around the frame width or 2 to 3 times that.
- I used Polygonal Lasso tool to restrict my brush strokes in the corners, in this first step.
- In this step I used Burn tool only. Doesn't really matter though.
In this step I went through all the corners with about 1-3px brush size. You could also use like frame width size to add slightly larger highlights and or darker areas.
Here's a video I uploaded on youtube showing how I brushed in the corners.