Most students of plots reject icons as stand-ins for bars or columns. They distract readers from the figures that matter. Some examples of the practice reinforce the objection.
To its credit, Dykema Gossett MA 2017 [pg. 5] plucks an appropriate icon for growth, but the plant icons nevertheless divert the reader’s attention from the two important numbers. Moreover, it is hard to know the y-axis scale.
DLA Piper RE 2017 [pg. 6] borrows its icons from the world of finance. To be precise, this graphic appears to size the iconic bull and bear in proportion to the percentages they represent.
Pinsent Masons Infratech 2017 [pg. 29] invokes a different role for icons — not as a stand-in for columns but as a pictorial version of column labels. This fillip contributes nothing but complexity.
KL Gates GCDisruption 2017 [pg. 13] has nine icons to the right of the 14-bar plot (The snippet captures only part of the page-tall plot.) Not only do the icons not match the bars, five of them have dotted borders and four have solid borders. If no distinction is drawn, it is superfluous to vary the borders.
Reed Smith Lifesciences 2015 [pg. 17] scattered random icons of integrated circuits around an array of area-circles. Confusion is the likely effect.