The files are part of the mwe
package and can be found in
/usr/local/texlive/2018/texmf-dist/tex/latex/mwe
on a TeX Live distribution; they're found automatically, so knowing the location is not necessary for including them. It might be for copying one of them, but with a smart OS that's not required as well. Indeed, with bash
syntax
cp $(kpsewhich example-image.png) .
will copy the file example-image.png
to the current directory, taking it from the appropriate place in the TeX Live distribution.
Here's an annotated list; where .{eps,jpg,pdf,png}
appears, it means that the image is available in all four formats.
% bordered rectangles with axes and diagonals and possibly a big letter in the middle
example-image.{eps,jpg,pdf,png}
example-image-a.{eps,jpg,pdf,png}
example-image-b.{eps,jpg,pdf,png}
example-image-c.{eps,jpg,pdf,png}
% images in the stated format showing it in the middle
example-image-1x1.{eps,jpg,pdf,png}
example-image-4x3.{eps,jpg,pdf,png}
example-image-10x16.{eps,jpg,pdf,png}
example-image-16x10.{eps,jpg,pdf,png}
example-image-16x9.{eps,jpg,pdf,png}
example-image-9x16.{eps,jpg,pdf,png}
% sides in golden ratio
example-image-golden.pdf
example-image-golden-upright.pdf
% page sized images
example-image-a3.pdf
example-image-a3-landscape.pdf
example-image-a4.pdf
example-image-a4-numbered.pdf
example-image-a4-landscape.pdf
example-image-a5.pdf
example-image-a5-landscape.pdf
example-image-letter.pdf
example-image-letter-numbered.pdf
example-image-letter-landscape.pdf
% the basic rectangle with axes and diagonals used to build the other images
example-image-empty.pdf
% the basic rectangle with just the gray background
example-image-plain.pdf
graphicx
feature, they were include in the TeX distribution, instead!kpsewhich example-image-duck.pdf
. The directory where these files are located usually equals the package name.hawaiian-pizza .png
example file in your honour.