I usually have a very strong (feeling unbearably itchy) trypophobic response to anything "organic" that has clusters of protrusions or holes e.g. lotus seed pods, but none of these examples have any such effect. I think it's because of the bright colours and low resolution.

Ditto, it has to be organic for me. Usually holes with stuff in it.

What about inorganic physical objects, like a shower head?

No problem if it's inorganic. I expect there must be some kind of evolutionary reason for it - the fact that it's an itching/crawling feeling strongly suggests it has/had something to do with bugs.