Most Spanish speakers pronounce ll and y the same. One of the most common realizations of this merged sound is [ʝ], the voiced palatal fricative. This sound is sometimes found as an affricate, [ɟʝ]. (For easy reference: [ʝ] is to [ɟʝ] what "sh" is to "ch".) The affricate version might appear when the sound is word- or phrase-initial, and after some consonants. It can also appear if the speaker is trying to emphasize the sound.
Besides this, there's always the possibility of so-called "free variation", that is, the speaker might pronounce a given phoneme using several variants chosen more or less at random. This can happen when the phoneme in question is not easy to confuse with others in the same language. Since the sound of ll~y is not very frequent and also not very similar to any other frequent phonemes in Spanish, speakers can afford to pronounce it somewhat carelessly, using variants that are that phonetically close to the basic, "standard" realization, because hearers aren't likely to mistake it for another consonant.