OK.
The sentence "僕ノ母ハ買物二行キマㇱタ" means "My mother went shopping." But that's not the issue I have with this sentence.
1) This sentence substituting the hiragana alphabet (ひらがな) with the katakana alphabet (カタカナ) makes this sentence unnatural in a written and read context. Katakana is generally used for loanwords, onomatopoeic sounds, emphasis, and for signing official documents (none of these cases are present here). I've also NEVER seen katakana be used for grammar particles at all...it is used for this purpose three times in that sentence.
2) The furigana (ふりがな/フリガナ; hiragana/kanatana reading) is incorrect AND inconsistent. For the case of "買物", the furigana on the album cover displays as "カとモノ" which is incorrect. The three katakana characters are used, all correct, and the hiragana character "と" all intermixed with those aforementioned characters. If we are being consistent with katakana, this furigana should read as "カイモノ" instead, or "かいもの" for hiragana. "と" should not be used at all.
I have no reference to how "my mother went shopping" relates to the Sonic Youth catalogue, as the tracklist of this record does not clearly allude to this anywhere. Maybe a song lyric? I am guessing there are many listeners who are aware of a connection.