"I think we've said our focus on those signature categories is where we're going to invest in product," said Mulligan during an exclusive interview with CNBC. "We're going to invest in presentation, marketing and bringing the newness to our guests and we saw our guests responding to the offering this quarter."
When it comes to food, the company will test and learn throughout 2015 and roll out changes next year, said Mulligan.
"We'll come back and provide a little bit more direction and begin to implement changes in food that we think will accelerate growth there," said Mulligan.
For the first quarter, Target's comparable sales grew 2.3 percent compared with a decrease of 0.3 percent in the same period last year.
In February, Target reduced its free shipping threshold to $25, according to Reuters. The change to the shipping policy is an attempt to engage shoppers. Online shopping leads to increased store sales, said Mulligan.
"The net is we see incremental profitability," said Mulligan.
Read MoreTarget's Lilly Pulitzer launch ignites shopping frenzy
Mulligan also touched on the Lily Pulitzer items available at Target, saying that a team was investigating the website's crash and preventing it from happening again, especially in preparing for Black Friday.
On the day the product line was launched, Target's website crashed, preventing shoppers from purchasing the products. Excessive demand in Target's brick and mortar stores also had many shoppers leave empty handed.
"We're disappointed in ourselves," said Mulligan. "Our expectation is that we provide a great guest experience regardless of where the guest interacts with us."