I'm having a bit of trouble differentiating these, and I'm wondering if it's because these are generally fuzzy concepts and nobody cares much, if I haven't read into it enough, if my innate assumptions about spoken language are obfuscating the definitions, etc.
Consider this: The ⃠ (No, not allowed, banned, etc) symbol is considered a pictogram, which by the format of the answer to the linked question, is a subset of the ideograms. However, it is usually seen composed with other pictograms (such as ⃠ 💩 superimposed), or coupled with another ideogram. If written Chinese is often taken as logographic, not ideographic, since logograms are defined as representing morphemes, basic units of meaning, rather perhaps more nebulous notions represented by ideograms (which I suppose all the major religous symbols would fit, e.g. dharmacakra☸, arguably ichthys, orthodox cross☦, peace symbol ☮, etc), then would the composition of this pictogram with a Chinese logogram now be a pictogram or a logogram? I find it tough to decide since it doesn't necessarily have a word in that language which represents it, since some words or emerging ideologies don't have clear antithetical terms, but sometimes they do? While nuclear weapons are arguably not an ideology, would the classic "no nuclear weapons symbol" fit into any category neatly?
Finally, i'm not really sure if a difference based on "idea, concept" vs "word, morpheme" vs "symbol representing concept which bares resemblence to physical manifestation" is that sensible, since aren't words pretty much abstract, conceptual "placeholder" symbols. I'm not well read on linguistics at all, so I don't know if Ludwig Wittgenstein is discredited, but he felt humans communicated by mapping "mental images" to words.
Inspiration: From Relation between some linguistics terms we have:
logogram or logograph - represents a morpheme or word, e.g. the Mandarin copula ⟨是⟩; ⟨&⟩ 'and', ⟨@⟩ 'at', ⟨$⟩ 'dollar' in English
ideogram or ideograph - represents an concept, e.g. ⟨上⟩ 'up' in Chinese/Japanese; digits like ⟨8⟩ 'eight'; ⟨♡⟩ 'love'; the no symbol ⟨ ⃠ ⟩; the red octagonal stop sign
pictogram or pictograph - an ideogram consisting of a pictorial representation of its referent, e.g. ⟨木⟩ 'tree' in Chinese/Japanese, ⟨💩⟩ 'pile of poo', many emoticons, astronomical symbols like ⟨☽⟩ 'waxing crescent moon'