Context: LaTeX is a typesetting system. When compiling a document, a lot of really in-depth debugging information is printed, which can be borderline incomprehensible to anyone but LaTeX experts. It can also be a visual hindrance when looking for important information like errors.
If you're trying to do pixel adjustments of figure position and changing it breaks something, you missed the point of the software package and/or are doing something horribly wrong and unsupported.
Sheesh, now I feel actually attacked a little. I was being mostly hyperbolic, but you can do really useful things with complex figures in presentations. For example: revealing elements sequentially to build up to the final figure or altering opacity of different elements to bring the audience's attention to specific parts of the figure.
This sequencing can sometimes very subtly alter the size of the figure as you change elements, so the default positioning will slightly change from one slide to the next. Most people won't care or notice when a figure slightly drifts by a pixel or two during these sequences, but it bothers me tremendously so I add adjustments to keep every variation of the figure aligned on the slides.