|Presumably a stock photo|
I am trying to figure out which East Mediterranean Roman amphorae came that small. Most small amphoras start off at twice that height (the things were made for bulk transport after all). There are some ancient Greek ones 35-40 cm tall, but these are bulbous, flatter based (Marseillaise 2 for example, from the end of VI to the beginning of IV Century B.C., Samos from VII to the beginning of V Century B.C.). The only Roman amphora that this might correspond with is 'Keay LII' made in Calabria and Sicily (4th cent onwards can be 40 to 50cm high), but that does not have a tapered base, nor - since it had a pretty local distribution and in the western Mediterranean - should it be occurring in any quantity in the Cyclades.
Another source however describes the vessel as an amphoriskos (with the neck and handle partially detached), which would suit, but then they in tern tend to be much smaller. Anyway whatever it is, they should not have been trying to walk off with it.
'German couple stopped at Milos airport with amphora', Ekathimerini.com , Sunday August 17, 2014
UPDATE 17th August 20:20.
It may be significant that the page with this report now seems to be inactive.