Narkissos....The inferrence is interestingly made in the Vulgate which has simul rapiemur cum here.
Jeffro...Well, I mentioned the interpolation of "Jehovah" in the NT which gives you 237 "serious errors" right off the bat. Here is example of a rendering that illustrates what is wrong with the NWT imho:
Philippians 2:6: "[Christ Jesus], who, although he was existing in God's form, gave no consideration to a seizure, namely, that he should be equal to God".
I find this to be very unnatural, if not grotesque, English and the added words are part of this (note that this is not a literal translation). "Although" is meant to clarify the concessive force of huparkhón, but its inclusion plus the rendering of this participle "existing" into a verbal predicate (which is often necessary to smooth the heavy use of participles in Greek into more natural English) obscures the relation between what follows and the initial "who", i.e. "who, being in the form of God, did not think..." vs. "who, although he was in the form of God, did not think..." In other words, dreadful English style. Then, having changed huparkhón from a non-finite participle to a finite verb, they do the opposite with égésato by nominalizing it -- thereby requiring even more verbiage ... requiring a new main verb "gave" and the nominal suffix to the verb. The verbiage adds to the woodenness but it is typical of the NWT (cf. "taking in knowledge" for "knowing", exercising faith" for "believe", etc.). Then harpagmon is literally rendered as a noun, but "a seizure" in modern English does not necessarily convey the same thought as the more wordy but clear "a thing to be grasped" or "something to be held onto". If they wanted to use that word, it would have been better to say "an act of seizure"; seizure by itself makes it sound like Jesus refused to give himself epilepsy. The whole phrase is very unnatural in English....a robber planning a heist would not say, "Okay, let's consider having ourselves a seizure". Next the insertion of "namely" makes for a much looser connection between "a seizure" and "that he should be equal to God". In the Greek, both these phrases are equivalent, i.e. "He did not consider X(acc) Y(acc)," like saying "He did not consider [Tom] [a fool]". But the rendering eliminates the parallelism by turning the noun phrase "equality with God" into a clause "that he should be equal to God", hence the "namely". Finally, it is an exegetical move to turn "equality with God" (which by itself does not claim whether or not this is a status he already had) into the expanded clause "that he SHOULD BE equal to God" (which contains within it an implicit claim that this is a status he did not already have).
Having said this, I do not consider the rendering of harpagmon by the word expressing an act of seizing as necessarily wrong or correct...this is a notorious crux interpretum and is hotly debated in scholarship, and I think the wording is ambiguous (intentionally so?) as to whether Jesus already had "equality with God" prior to the incarnation but gave it up, or went into a course that was opposite of seizing "equality with God".