Aside from actual idol worship, it is also forbidden to engage in activities that will appear as if a person was bowing down before an idol. Based on this concept, the Gemara on today’s daf (=page) quotes a baraita that teaches that if someone drops coins in front of an idol he should not bend over to pick them up, if it appears as though he is bowing to the idol. Similarly, if a public drinking fountain is built with a face so that the water flows from its mouth, a person may not place his mouth on the mouth of the figure in order to drink, since it appears as if he is kissing the idol.
This water fountain was in use in Pompeii during the time of the Mishnah. In many places in the ancient world – and in some places to this day – it was common for public drinking fountains to be built for general use. Sometime these fountains were simple pipes, but in many places the mouth of the fountain was made into shapes, oftentimes in the figure of a face. While most of these decorative features were made simply to beautify the public area, occasionally the faces were those of idols. This led to a concern lest drinking directly from such fountains may appear to be kissing an idol, which would be forbidden.
Tosafot Hakhmei Anglia ask whether the same concern existed with regard to picking up coins that have dropped, if they have on them an engraved form, perhaps even an engraving of an idol. They argue that forms that are minted onto coins are certainly not placed there for purposes of worship and there is no need to be concerned that bending over to pick up coins with such forms on them might be misconstrued as praying to them.