Why does the sun feel warmer from a reflection than it does straight on in this situation?

Factual Questions
1

On my morning dog walk, there’s a place where I’m in the shadow of a house to the east but I’m hit with the light from the sun reflecting on a window from a house across the street on the west. Something like this:

At point A I’m in the shadow of the east house. If I look at the sun beam reflecting off the window, it feels very warm on my face. At point B, I’m in the sunbeam itself. If I look at the sun directly, it doesn’t feel as warm on my face as it does when it’s reflected off the window. This surprises me since I would think the sun from the window would be less intense. Some light is lost by going into the house and the reflected light is scattered more. It seems like the beam of sun directly hitting my face at point B should feel warmer than the reflected light at point A. But instead, it feels like the sun light is being magnified when it’s reflecting off the window. What would explain this apparent temperature difference that makes the reflected light feel warmer than the direct light?

2

Maybe you’re also getting some heat from the houses themselves?

3

Maybe the house on the right is helping to trap heat at point A, but once you’re at point B you’re now exposed to colder air that’s (north?) of the house on the right.

4

The window might be slightly curved, and thus focussing the light on a smaller area, increasing its intensity.

5

Hypothesis: Could it be a relative difference between heated and non-heated skin?

i.e. assuming the same sunlight either way, would either one feel warmer:

  • A small, 2-inch patch of it surrounded by unheated skin (reflected by the window)
  • Uniform heating of the skin across the whole body (direct sun)

Does the skin do this sort of “relative” temperature monitoring, comparing the heated patch vs the adjacent unheated patches?

Illustration:

Would either one “feel” hotter?

6

I didn’t think to look at the shadowed face of the east house to see how the light hits it. If the light is being scattered from a flat window, then the face of the east house should be bathed evenly in light. If the window is curved and focusing the light, then I should see a bright spot. I’ll check tomorrow and see what the reflected light looks like.

7

If you’re going to be out there anyway, maybe download a light sensor app for your phone beforehand? Then you can actually measure the light intensity in both scenarios to see if it’s an actual difference in lighting or a perception thing from your body.

8

Looking at the reflections from most house windows, I’ve noticed that virtually all of them are curved, and appear to be concave, viewed from the outside. It’s by no mean a regular spherical curvature, but it will tend to focus light into smaller spot than a mirror would give, at a certain distance (beyond a certain point, after afocal region, th light will tend to disperse again. So this will only work over relatively short distances.)

The windows of the Vdara hotel and spa in Las Vegas, collectively, act as a giant cylindrically concave mirror and concentrate sunlight. It’s been known to melt plastic bags left by the pool.

9

The so-called “Walkie Talkie Building” (officially “20 Fenchurch Street”) in London was designed by the same architect, and has been known to melt the bodywork of cars and used to fry eggs.