Is there a word that means "appears like an exact copy but actually isn't"
"The copies of texts transcribed by the monks were usually XXX because of inevitable human error."
"Her lack of resources meant that her outfits were XXX of the ones she saw in fashion magazines."
"The unicode characters '05AD' and '0596' are XXX"
EDIT - for further context, which should have been added by the poster, the unicode characters '05AD' and '0596' are two near-identical characters from the Hebrew alphabet. A less demanding example might have been "em dash" and "en dash", or a lowercase L ("l") and the numeral for one ("1").
- Simulacrum - "a slight, unreal, or superficial likeness or semblance."
Her lack of resources meant that her outfits were "replicas"/"rough imitations"/"crude copies" of the ones she saw in fashion magazines.
replica - "any close copy or reproduction."
rough - "executed or ventured hastily, tentatively, or imperfectly"
crude - "not carefully or skillfully made; rough: a quick, crude sketch."
There are differences of nuance between your examples, and I'm not sure there's a single word that covers all cases equally well.
"The copies of texts transcribed by the monks were usually word because of inevitable human error."
In this case, they tried to make them the same, but error crept in, so I would say they are imperfect copies. This implies that there are detectable differences, and it is those differences that matter.
"Her lack of resources meant that her outfits were word of the ones she saw in fashion magazines."
Here we want to get across that the outfits are an attempt to copy the originals but with less investment of time, effort or expense, and lack authenticity. So, I would say they are imitations. This carries both senses of "a result or product of imitating" and "a counterfeit; copy".
"The unicode characters '05AD' and '0596' are word"
In this case, they are logically different, but with similar appearance, so I would say they are deceptively similar. Here, the logical difference is what is important, and the similarity causes confusion.
- lookalikes
- facsimile
- clones
Your first examples are derivative works, inferior copies, but en-dash and em-dash are not accidentally different, there is not an original-vs-copy relationship there.
Ersatz - "made or used as a substitute, typically inferior to the thing copied"
Doesn't really work for any of your examples but the first one as phrased, but I think it might serve your purposes in some cases.
In response to the first comment: the definition I originally provided was simply from memory. Here is the Oxford Online definition:
1 (Of a product) made or used as a substitute, typically an inferior one, for something else: 'ersatz coffee'