It introduces several new concepts along the way, some of which are unique to GNU make. The first, and perhaps the most obvious, is that I did not explicitly list all the .fig or .eps files. Listing all the files requires me to update the makefile each time I add a figure, which is rather error-prone. Using the GNU make wildcard function allows the makefile to automatically update the files correctly, no matter how many figures you add. If you choose to use it, be careful that you really mean to list all the files, and be aware that it will not work under most commercial vendors' versions of make.
GNU make has many functions like wildcard.
The name of the function comes first, with the argument, or comma-seperated list of arguments, following. Pattern rules may by preferable if you are writing makefiles for yourself or for projects where you can guarantee that GNU make will be used, and suffix rules are preferable if you are trying to write portable makefiles for all platforms. The reason pattern rules are more powerful than suffix rules is they can match any sort of pattern, not just suffixes. Patterns are a more general concept than suffixes, and can be used in other ways in other kinds of rules. The GNU Make manual has examples of this.