In the past decade I've seen a variety of changes made by the northern Nevada combined electric/gas utility on this matter. My experience might shed some light on the issue in other places.
To start with, utilities have requirements as to where the service will be set. These days, it's typically within a few feet of the corner of the building closest to the utility feed. All such locations have to be approved by the utility before connection is made. So, for the pictured installation above, I'd first verify that both services are properly located.
That brings up issue #2: how the rules change over time. My utility once WANTED the electrical and gas meters grouped together; all around town you can find installs with the electric meter directly above the gas meter, with the gas equipment inside what we would call our 'working space,' This is no longer allowed, and a service change means you get to relocate the service.
Now, just what IS the rule for gas and electric placement? Well, my PoCo specifies 36" clearance, as measured from the center of the regulator (that funny-shaped big round thing) and the nearest electrical thing that can spark. For example, a circuit breaker or disconnect switch. Meter bases and junction boxes don't ordinarily spark. This 36" is measured in a direct line between the location of the 'spark' and the center of the regulator. The measurement is the shortest distance - and NOT a vertical or horizontal measurement. A simple 'connect the dots' tape measure measurement.
It's very possible that the exact requirements will vary by PoCo, especially when the two utilities are different firms. Most have their standards available, free, on the internet. Check for the exact wording of their rules.
As for the picture above, I suspect that a service change was made without relocating the electrical service.