The tariffs don't directly impact Shopify as it essentially acts as a middle man for merchants. In fact because it works off a gross transaction volume basis, if merchants were to increase prices to offset tariffs it could even benefit Shopify. However, this is probably a goldilocks scenario and the more likely situation is sales slow down in regards to merchants. It is highly unlikely merchants could pass on 100% of tariff impacts to consumers and not notice a slowdown in sales.
If tariffs got bad enough ,they could even see some merchants churn off the platform due to declining sales.
At this point in time the large drawdown in Shopify's price is more so on the risks that we enter a global recession because of tariffs, not because of anything tariffs will do to the actual business, if that makes any sense.