Kabbalah makes it absolutely clear that the "image" one receives of a "malach" (angelic messenger), is for the personal convenience and benefit of the one who is "seeing" that image. The anthropomorphic image of a "god" or "spirit messenger," is actually formed in the mind of the "seer," always in accordance with his or her specific conditioning and mindset at the time. In other words, while you might "evoke" the "image" of an "angel" in the "crystal," that image is not the actual presence of the "spirit intelligence" being "summoned."
Fundamentally all "imaging" of "Spiritual Intelligences," of the "Eternal Living Spirit," etc., are as transitory as anything else in manifestation, and the images will fade if you sit long enough. Of course, the "image" of an "angelic being" may be appropriate to the one who is "seeing" it, but it is definitely not appropriate to that which is "seen," as Elliot R. Wolfson explained in "Through a Speculum that Shines: Vision and Imagination in Medieval Jewish Mysticism," an outstanding text dealing this very topic.
In offering this response to a querant, I was informed that whilst he concurs with me, he would still like to have my thoughts on the "ethical aspect" when it comes to conjurations reading "In the name of [Divine names] I command you to appear in comely shape....," etc. I was equally informed that numerous adjurations of this nature appears in "grimoires," and that they "work" because "visions" will appear if "you stay with it."
To this my response is simply, I have no trust whatsoever in ANY images of whatever nature appearing in crystals, or in visions of whatever nature, beyond perhaps the revelation of something possibly meaningful to the "seer," as in the case of the prophets of old. This is more or less the stance of Jewish mystics who carefully investigated and addressed this topic. In other words, the "images" which the individual in question sat so long to see, will, as said earlier, disappear if he continues to sit long enough. In fact, nothing really remains to be said on this matter.
Now, regarding the idea of forcibly "commanding" spirit intelligences "to appear in comely shapes," and to execute whatever is commanded without question, let me put it simply, whilst this is the way in which those who wrote those "grimoires" fancy themselves gaining control over every living force on earth and in the heavens, the stance of "Practical Kabbalah" is somewhat different. There is no general assumption that the universe and all its denizens were created for us to make, break and command in any way we deem fit, and that all and sundry must simply scrape up to our human wills and fulfill every selfish human whim. Such is plain nonsense!
In the main, the traditional adjurations of "Kabbalah Ma'asit" (Practical Kabbalah) commence with an acknowledgement of Divine authority over "All," hence, above all else, they attempt to align with "Divine Will." Thus one often encounters the adjurations of this Tradition commencing with a standard formula which reads "Y'hi ratzon milfanecha.....," i.e. "May it be in accordance with Your will....."
It should be noted that there are numerous differences between the ritual practices of this Tradition and those which are pandered around in the popular "grimoires." The ritual procedures of one Tradition should never in any way be mistaken for those of another. Plainer still, the specific "ethical issues" which the individual in question is finding so bothersome in terms of the "grimoires" he perused, are not applicable to "Practical Kabbalah"!