Figurative meaning of 「総動員{そうどういん}する」 with 語彙{ごい}

Question

Context: these are thoughts of the one who 冬馬{とうま} is teaching to play the guitar.

だって、心地良いから。
冬馬が、俺のミスを一生懸命探すのが。
冬馬が、俺の拙い指の動きを笑うのが。
冬馬が、俺を[貶す]{けなす}ために、いつもは貧しい語彙を、今だけ総動員するのが。

The problem areas are marked bold. I understand that the one thinking finds Touma's behavior pleasant (although the actions are not polite...) and lists examples of it. I think I understand everything until the last one.

• 俺を[貶す]{けなす}ために: to speak ill of me
• いつもは貧しい語彙を: her usually poor vocabulary?
• 今だけ総動員するのが: "mobilize" only for this time?

1. I don't understand how は changes the meaning of いつも. Is the vocabulary "poor as usual" or "usually poor but not this time"?
2. Related to the previous meaning, can 総動員する in some contexts (maybe even here) mean "finding nice words" or is it like the previous sources of pleasure, "finding especially rude words"?

Answer 1

1. This は is an exemplary case of the contrastive は. So it means "usually, but not this time." "Poor as usual" would be something like "いつも通り貧しい" or "いつものように貧しい." Overall meaning may not change with or without the contrastive は, but it does add nuances and the sentence definitely sounds a lot better for its presence in this case.

2. "総動員する" means "to mobilize all the personnel of (a unit)," and on its own does not have anything to do with finding words, whether nice or rude. "語彙を総動員する" is indeed a figurative way of speaking, likening your vocabulary to an arsenal or army of words, the entirety of which is mobilized for the purpose of, in this particular case, verbally annihilating your opponent (who, somehow, seems to draw pleasure from it.)

(I should probably add that the phrase can be used in a variety of contexts, not limited to when insulting people. There's a lot of examples on google.)