Idols: pictures or vehicles?

In a lot of religions, the deities are believed to enter into images. This applies in modern Hinduism and Shenjiao (China), and in Ancient Egypt. The Egyptian ritual — opening the mouth — is documented and the Chinese one — opening the eyes — can be seen on youtube.

This idea didn't seem to occur in Hellenism, to judge by the documentations. Maximus of Tyre and Porphyry speak of statues as symbolic, and Iamblichus' account of Egyptian beliefs seems to suggest they are foreign to the Greeks. On the other hand, the washing and dressing of cult statues in many temples was the same as the Hindu practice. The Egyptian and Hindu practice of the temple image processing through the streets was rare, but it did occur — at the Athenian Urban Dionysia, for example.

Has anyone any thoughts on this?

I also see them as symbols. I think dressing the statue of Athena would be seen as some sort of offering to the goddess but doesn't mean that her statue is actually her or that she lives in it or anything like that. I think the rituals are performed in order to honour the Gods 9and in certain instances to try to get closer to them spiritually).

I've just found an interesting work that's relevant to this topic. A PhD thesis by Polly Weddle, called "Touching the gods: physical interaction with cult statues in the Roman world". I'm still reading it, and I haven't followed up the references, but it does seem to suggest that the popular view was closer to the Hindu position.
http://ethos.bl.uk/OrderDetails.do?did=2&uin=uk.bl.ethos.526273

The lack of a standard consecration ritual in Greece, like those in ancient Egypt and modern China, is clearly not important, as it seems there's no standard procedure in Hinduism.

It would have depended some on the situation, but yes, in general, at least for cult images, the deity would indeed be considered to dwell in the image by means of a numinous presence, or by way of a daemon allied to that deity.

No, it would certainly not be considered that the image itself was literally or fully the deity, but there would be a certain kind of presence; i.e. a cult image was not merely a piece of metal, wood or stone.