Brighten? Nooooo, I think not. But it did make me shake my head and give one of those despairing chuffs of laughter. Then I put my head down on my desk for a while. Once I get home from work and have a beer, I'll be fine. BYW what in the world kind of "scale" was that?
I know I am going to regret this, and I am sure you are all going to think I am a complete egg head, but I could in theory see why this would be a sensible scale as an initial recording.
You will note the thermometer (that is what it is) reads about 28 celcius. 80 Degs F. At those temps it could be reasonably humid? It might be unseasonably warm?? We all know latent deposition can be effected by such environmental conditions. There might be very good reason for recording this information. I always record the weather conditions in my reports. You never know when it might add weight to testimony.
A scale in a photograph does not need to be a device with inch or mm deliniations.
It can be a size that is standard, i.e. business card, 3.5 index card, package of cigarettes, etc. Printing a photo at 1:1 scale just has to reproduce the standard used in the photo.
Technically, a 'scale' does not even have to be a 'standard' size, as long as the item used is retained in the case file, and is available as a reference when sizing (or viewing) photos.
I once considered using a laboratory triple-beam scale in a photograph of a latent palmprint... Unfortunately, the triple-beam scale wouldn't fit in a manila folder.