No smoking in three different sign vessels

Three signs I spotted while walking through the Central Railway Station in Helsinki, Finland. All three signs show classical variations of "No Smoking" signs with red slashed circle indicating "NO" over an iconic cigarette that has partially burned with a clear trail of smoke. As a side comment, I tend to think that the trail of smoke serves several purposes:

1. It clarifies the image that we are not depicting some other cylindrical objects.

2. It emphasizes that we are not forbidding cigarettes as an object, but the act of smoking.¹

3. It is implying that the reason we are forbidding smoking is the smoke that can cause discomfort for other people.

But what struck me here was the progression of diminishing efforts in the sign vessel. The first sign was a manufactured plaque, bolted to a brick wall. The second was a laminated A4 screwed onto a wooden panel wall, and the last one just an A4 in a plastic cover, taped and/or stapled to the wooden panel wall. Maybe the original sign was not enforcement enough, and the latter signs were added to strengthen the message, though with less and less enthusiasm. Admittedly, the latter two signs were in a temporary construction area wall, but even between them we have a difference on how much effort was put into them.